Borylimide catalysts

ABSTRACT

The present invention provides a borylimide catalyst and further relates to compositions comprising the borylimide catalysts and processes for the polymerisation of olefins (e.g. ethylene) using the borylimide catalysts or the compositions comprising the borylimide catalysts.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage filing, under 35 U.S.C. §371(c), of International Application No. PCT/GB2019/053263, filed onNov. 19, 2019, which claims priority to European Patent Application No.18207325.4, filed on Nov. 20, 2018. The entire contents of each of theaforementioned applications are incorporated herein by reference.

INTRODUCTION

The present invention relates to borylimide catalysts. The presentinvention also relates to compositions comprising the borylimidecatalysts and processes for the polymerisation of olefins (e.g.ethylene) using the borylimide catalysts or the compositions comprisingthe borylimide catalysts.

BACKGROUND OF THE INVENTION

It is well known that ethylene (and α-olefins in general) can be readilypolymerized at low or medium pressures in the presence of certaintransition metal catalysts. These catalysts are generally known asZeigler-Natta type catalysts.

Subsequent catalyst developments in this field led to the discovery ofmetallocene catalysts, constrained geometry catalyst (CGC) complexes andmore recently, post-metallocene systems, whereby one or more of thecyclopentadienyl ligands of the metallocene catalyst systems arereplaced by a different moiety [Gibson & Spitzmesser, Chem. Rev. (2003),103, 283-315].

Adams et al. (Organometallics, 2006, 25 (16), 3888-3903) and Bigmore etal. (Chem. Commun., 2006, 436-438) disclose ethylene polymerizationcatalysts which are N-alkyl or N-aryl imido substituted titaniumcomplexes containing polydentate ligands.

Nevertheless, despite the advances made by metallocene, CGC complexesand more recently post-metallocene catalysts, there remains a need fornew non-metallocene catalysts capable of effectively polymerizingolefins. It is desirable that such catalysts are highly active and leadto polyolefins exhibiting high molecular weight and/or lowpolydispersity.

The present invention was devised with the foregoing in mind.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided acompound of formula (I):

wherein:

-   M is selected from titanium, zirconium and hafnium;-   X¹ and X² are independently selected from halo, hydrogen, a    phosphonate, sulfonate or boronate group, amino, (1-6C)alkyl,    (1-6C)alkoxy, aryl, aryloxy and heterocycloalkyl (such as THF),    wherein said (1-6C)alkyl, (1-6C)alkoxy, aryl and aryloxy groups may    be optionally substituted with one of more groups selected from    halo, oxo, hydroxy, amino, nitro, (1-6C)alkyl, (2-6C)alkenyl,    (2-6C)alkynyl, (1-6C)haloalkyl, (1-6C)alkoxy, aryl and    Si[(1-4C)alkyl]₃;-   Y is BR¹R²;-   Z is a polydentate ligand coordinated to M by at least 2 donor atoms    Q, wherein each Q is independently selected from N, O, S and P;-   R¹ and R² are independently selected from NR³R⁴, OR⁵, SR⁶ and    CR⁷R⁸R⁹;-   R³, R⁴, R⁵, R⁶, R⁷, R⁸ and R⁹ are independently selected from    hydrogen, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, aryl and    heteroaryl, wherein said (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl,    aryl and heteroaryl groups are optionally substituted with one or    more substituents selected independently from halo, hydroxy, amino,    nitro, (1-6C)alkyl and (1-6C)haloalkyl;-   or R¹ and R² are linked, such that when taken in combination with    the boron atom to which they are attached, they form a group:

-   -   wherein ring A is a carbocyclic or heterocyclic ring, optionally        substituted with one or more substituents selected independently        from halo, hydroxy, amino, (1-6C)alkyl, (1-6C)alkoxy,        (1-6C)haloalkyl, aryl and heteroaryl, wherein said aryl and        heteroaryl groups are optionally substituted with one or more        substituents selected independently from halo, hydroxy, amino,        nitro, (1-6C)alkyl and (1-6C)haloalkyl.

According to a second aspect of the present invention there is provideda composition comprising a compound according to formula (I) as definedherein immobilised on a solid support material.

According to a third aspect of the present invention there is provided aprocess for the polymerisation of at least one olefin, the processcomprising the step of contacting the at least one olefin with acompound having a structure according to formula (I) as defined herein.

DETAILED DESCRIPTION OF THE INVENTION Definitions

The term “(m-nC)” or “(m-nC) group” used alone or as a prefix, refers toany group having m to n carbon atoms.

The term “alkyl” as used herein refers to straight or branched chainalkyl moieties, typically having 1, 2, 3, 4, 5 or 6 carbon atoms. Thisterm includes reference to groups such as methyl, ethyl, propyl(n-propyl or isopropyl), butyl (n-butyl, sec-butyl or tert-butyl),pentyl, hexyl and the like. In particular, an alkyl may have 1, 2, 3 or4 carbon atoms.

The term “alkylene” as used herein refers to straight chain bi-valentalkyl moieties, typically having 1, 2, 3, 4, 5 or 6 carbon atoms. Thisterm includes reference to groups such as methylene (—CH₂—), ethylene(—CH₂CH₂—), propylene (—CH₂CH₂CH₂—) and the like. In particular, analkylene may have 1, 2 or 3 carbon atoms.

The term “alkenyl” as used herein refers to straight or branched chainalkenyl moieties, typically having 2, 3, 4, 5 or 6 carbon atoms. Theterm includes reference to alkenyl moieties containing 1, 2 or 3carbon-carbon double bonds (C═C). This term includes reference to groupssuch as ethenyl (vinyl), propenyl (allyl), butenyl, pentenyl andhexenyl, as well as both the cis and trans isomers thereof.

The term “alkenylene” as used herein refers to straight chain bi-valentalkylenyl moieties, typically having 2, 3, 4, 5 or 6 carbon atoms. Thisterm includes reference to groups such as ethenylene (—CH═CH—),propenylene (—CH═CHCH₂—) and the like, as well as both the cis and transisomers thereof. In particular, an alkenylene may have 2 or 3 carbonatoms.

The term “alkynyl” as used herein refers to straight or branched chainalkynyl moieties, typically having 1, 2, 3, 4, 5 or 6 carbon atoms. Theterm includes reference to alkynyl moieties containing 1, 2 or 3carbon-carbon triple bonds (C═C). This term includes reference to groupssuch as ethynyl, propynyl, butynyl, pentynyl and hexynyl.

The term “haloalkyl” as used herein refers to alkyl groups beingsubstituted with one or more halogens (e.g. F, Cl, Br or 1). This termincludes reference to groups such as 2-fluoropropyl, 3-chloropentyl, aswell as perfluoroalkyl groups, such as perfluoromethyl.

The term “alkoxy” as used herein refers to —O-alkyl, wherein alkyl isstraight or branched chain and comprises 1, 2, 3, 4, 5 or 6 carbonatoms. In one class of embodiments, alkoxy has 1, 2, 3 or 4 carbonatoms. This term includes reference to groups such as methoxy, ethoxy,propoxy, isopropoxy, butoxy, tert-butoxy, pentoxy, hexoxy and the like.

The term “aryl” or “aromatic” as used herein means an aromatic ringsystem comprising 6, 7, 8, 9 or 10 ring carbon atoms. Aryl is oftenphenyl but may be a polycyclic ring system, having two or more rings, atleast one of which is aromatic. This term includes reference to groupssuch as phenyl, naphthyl and the like. Unless otherwise specification,aryl groups may be substituted by one or more substituents. Aparticularly suitable aryl group is phenyl.

The term “aryloxy” as used herein refers to —O-aryl, wherein aryl hasany of the definitions discussed herein. Also encompassed by this termare aryloxy groups in having an alkylene chain situated between the Oand aryl groups.

The term “heteroaryl” or “heteroaromatic” means an aromatic mono-, bi-,or polycyclic ring incorporating one or more (for example 1-4,particularly 1, 2 or 3) heteroatoms selected from nitrogen, oxygen orsulfur. Examples of heteroaryl groups are monocyclic and bicyclic groupscontaining from five to twelve ring members, and more usually from fiveto ten ring members. The heteroaryl group can be, for example, a 5- or6-membered monocyclic ring or a 9- or 10-membered bicyclic ring, forexample a bicyclic structure formed from fused five and six memberedrings or two fused six membered rings. Each ring may contain up to aboutfour heteroatoms typically selected from nitrogen, sulfur and oxygen.Typically, the heteroaryl ring will contain up to 3 heteroatoms, moreusually up to 2, for example a single heteroatom.

The term “carbocyclyl”, “carbocyclic” or “carbocycle” means anon-aromatic saturated or partially saturated monocyclic, or a fused,bridged, or spiro bicyclic carbocyclic ring system(s). Monocycliccarbocyclic rings contain from about 3 to 12 (suitably from 3 to 7) ringatoms. Bicyclic carbocycles contain from 7 to 17 carbon atoms in therings, suitably 7 to 12 carbon atoms, in the rings. Bicyclic carbocyclicrings may be fused, spiro, or bridged ring systems. A carbocyclic ringmay be fused to an aryl or heteroaryl ring.

The term “heterocycloalkyl”, “heterocyclic” or “heterocycle” means anon-aromatic saturated or partially saturated monocyclic, fused,bridged, or spiro bicyclic heterocyclic ring system(s). Monocyclicheterocyclic rings contain from about 3 to 12 (suitably from 3 to 7)ring atoms, with from 1 to 5 (suitably 1, 2 or 3) heteroatoms selectedfrom nitrogen, oxygen or sulfur in the ring. Bicyclic heterocyclescontain from 7 to 17 member atoms, suitably 7 to 12 member atoms, in thering. Bicyclic heterocyclic(s) rings may be fused, spiro, or bridgedring systems. A heterocyclic ring may be fused to an aryl or heteroarylring.

The term “halogen” or “halo” as used herein refers to F, Cl, Br or I. Ina particular, halogen may be Cl.

The term “substituted” as used herein in reference to a moiety meansthat one or more, especially up to 5, more especially 1, 2 or 3, of thehydrogen atoms in said moiety are replaced independently of each otherby the corresponding number of the described substituents. The term“optionally substituted” as used herein means substituted orunsubstituted.

It will, of course, be understood that substituents are only atpositions where they are chemically possible, the person skilled in theart being able to decide (either experimentally or theoretically)without inappropriate effort whether a particular substitution ispossible.

Borylimide Catalysts

According to a first aspect of the present invention there is provided acompound of Formula I

wherein:M is selected from titanium, zirconium and hafnium;X¹ and X² are independently selected from halo, hydrogen, a phosphonate,sulfonate or boronate group, amino, (1-6C)alkyl, (1-6C)alkoxy, aryl,aryloxy and heterocycloalkyl (such as THF), wherein said (1-6C)alkyl,(1-6C)alkoxy, aryl and aryloxy groups may be optionally substituted withone of more groups selected from halo, oxo, hydroxy, amino, nitro,(1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, (1-6C)haloalkyl,(1-6C)alkoxy, aryl and Si[(1-4C)alkyl]₃;Y is BR¹R²;Z is a polydentate ligand coordinated to M by at least 2 donor atoms Q,wherein each Q is independently selected from N, O, S and P;R¹ and R² are independently selected from NR³R⁴, OR⁵, SR⁶ and CR⁷R⁸R⁹;R³, R⁴, R⁵, R⁶, R⁷, R⁸ and R⁹ are independently selected from hydrogen,(1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, aryl and heteroaryl, whereinsaid (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, aryl and heteroarylgroups are optionally substituted with one or more substituents selectedindependently from halo, hydroxy, amino, nitro, (1-6C)alkyl and(1-6C)haloalkyl;or R¹ and R² are linked, such that when taken in combination with theboron atom to which they are attached, they form a group:

wherein ring A is a carbocyclic or heterocyclic ring, optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)haloalkyl, aryland heteroaryl, wherein said aryl and heteroaryl groups are optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl.

Substituent Y attached to the imido-nitrogen, defines the boryl-imidomoiety of the compounds of formula I. The boryl-imido moiety may becyclic or acyclic in nature. Suitable acyclic boryl-imido moietiescomprise carbon-linked or heteroatom-linked substituents attached toboron. In an embodiment, R¹ and R² are independently selected fromNR³R⁴, OR⁵, SR⁶ and CR⁷R⁸R⁹. In an embodiment, R¹ and R² areindependently selected from NR³R⁴, OR⁵ and SR⁶. In a further embodiment,R¹ and R² are both NR³R⁴. In another embodiment, R¹ and R² are bothNR³R⁴, and R³ and R⁴ are independently selected from hydrogen,(1-6C)alkyl, aryl and heteroaryl, wherein said (1-6C)alkyl, aryl andheteroaryl groups are optionally substituted with one or moresubstituents selected independently from halo, hydroxy, amino, nitro,(1-6C)alkyl and (1-6C)haloalkyl.

Suitable cyclic boryl-imido moieties comprise carbocyclic and/orheterocyclic rings. In an embodiment, R¹ and R² are linked, such thatwhen taken in combination with the boron atom to which they areattached, they form a group:

wherein ring A is a carbocyclic or heterocyclic ring, optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)haloalkyl, aryland heteroaryl, wherein said aryl and heteroaryl groups are optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl. Ring A maycomprise one or more unsaturated bonds. Ring A may be optionally fusedto an aryl or heteroaryl ring.

Preferably, ring A is a heterocyclic ring. In an embodiment, R¹ and R²are linked, such that when taken in combination with the boron atom towhich they are attached, they form a group:

wherein X is a heteroatom chosen from NR¹⁰, O and S;the heterocyclic ring A is optionally substituted with one or moresubstituents selected independently from halo, hydroxy, amino,(1-6C)alkyl, (1-6C)alkoxy, (1-6C)haloalkyl, aryl and heteroaryl, whereinsaid aryl and heteroaryl groups are optionally substituted with one ormore substituents selected independently from halo, hydroxy, amino,nitro, (1-6C)alkyl and (1-6C)haloalkyl; and R¹⁰ is (1-6C)alkyl, aryl orheteroaryl, wherein said (1-6C)alkyl, aryl and heteroaryl groups areoptionally substituted with one or more substituents selectedindependently from halo, hydroxy, amino, nitro, (1-6C)alkyl and(1-6C)haloalkyl.

In an embodiment, R¹ and R² are linked, such that when taken incombination with the boron atom to which they are attached, they form agroup:

wherein the heterocyclic ring A is optionally substituted with one ormore substituents selected independently from halo, hydroxy, amino,(1-6C)alkyl, (1-6C)alkoxy, (1-6C)haloalkyl, aryl and heteroaryl, whereinsaid aryl and heteroaryl groups are optionally substituted with one ormore substituents selected independently from halo, hydroxy, amino,nitro, (1-6C)alkyl and (1-6C)haloalkyl; and each R¹⁰ is independently(1-6C)alkyl, aryl or heteroaryl, wherein said (1-6C)alkyl, aryl andheteroaryl groups are optionally substituted with one or moresubstituents selected independently from halo, hydroxy, amino, nitro,(1-6C)alkyl and (1-6C)haloalkyl. In a further embodiment, each R¹⁰ isindependently (1-6C)alkyl or aryl, wherein said aryl group is optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl. In anotherembodiment, each R¹⁰ is independently (1-6C)alkyl or aryl, wherein saidaryl group is optionally substituted with (1-6C)alkyl or(1-6C)haloalkyl. In an embodiment, ring A is a 5- or 6-membered ring,such as a 5-membered ring.

In an embodiment, Y is selected from one of the following groups:

wherein each R¹⁰ is independently (1-6C)alkyl, aryl or heteroaryl,wherein said (1-6C)alkyl, aryl and heteroaryl groups are optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl. In afurther embodiment, each R¹⁰ is independently (1-6C)alkyl or aryl,wherein said aryl group is optionally substituted with one or moresubstituents selected independently from halo, hydroxy, amino, nitro,(1-6C)alkyl and (1-6C)haloalkyl. In another embodiment, each R¹⁰ isindependently (1-6C)alkyl or aryl, wherein said aryl group is optionallysubstituted with (1-6C)alkyl or (1-6C)haloalkyl. In another embodiment,R¹⁰ is (1-6C)alkyl, such as methyl, ethyl, propyl or isopropyl. In apreferred embodiment, at both instances, R¹⁰ is the same (1-6C)alkyl. Ina more preferred embodiment, both R¹⁰ are methyl. In a more preferredembodiment, both R¹⁰ are isopropyl.

In an alternative embodiment, R¹⁰ is an aryl group optionallysubstituted with one or more substituents selected independently from(1-6C)alkyl and (1-6C)haloalkyl. In a further embodiment, R¹⁰ is an arylgroup substituted with two substituents selected independently from(1-6C)alkyl and (1-6C)haloalkyl. In a yet further embodiment, R¹⁰ is thefollowing group:

wherein R¹¹ is (1-6C)alkyl or (1-6C)haloalkyl, such as (1-6C)alkyl (forexample isopropyl).

In a preferred embodiment, Y is selected from one of the followinggroups:

Z is a polydentate ligand coordinated to the metal (M) by at least 2donor atoms Q, wherein each Q is independently selected from N, O, S andP. The donor atoms Q bind to the metal and accordingly Z may be a bi-,tri-, tetra-, penta- or higher dentate ligand. Each Q atom may be thesame or different. In an embodiment, Z is a tri- or tetra-dentate ligandcoordinated to M by 3 or 4 donor atoms Q. In a further embodiment, Z isa tridentate ligand coordinated to M by 3 donor atoms Q. In a preferredembodiment, each donor atom Q is N.

In an embodiment, Z is a ligand according to formula II:

wherein Q¹, Q² and Q³ are NR¹²R¹³ or a heteroaryl group containing atleast one nitrogen atom, said heteroaryl group optionally substitutedwith one or more substituents selected from halo, hydroxy, amino, nitro,(1-6C)alkyl, (1-6C)alkoxy, —S-(1-6C)alkyl and (1-6C)haloalkyl;R¹² and R¹³ are independently absent, hydrogen, (1-20C)alkyl, aryl orheteroaryl as valency permits, wherein said (1-20C)alkyl, aryl andheteroaryl groups are optionally substituted with one or moresubstituents selected from halo, hydroxy, amino, nitro, (1-6C)alkyl,(1-6C)haloalkyl and aryl;L¹, L² and L³ are absent, a bond, (1-3C)alkylene or (2-3C)alkenylene,said (1-3C)alkylene or (2-3C)alkenylene moieties being optionallysubstituted with one or more substituents selected from (1-3C)alkyl,halo, hydroxy, (1-3C)alkoxy, aryl or heteroaryl;L⁴ is absent, CR¹⁴, [BR¹⁵]⁻, (1-3C)alkylene or (2-3C)alkylenylene, said(1-3C)alkylene or (2-3C)alkenylene moieties being optionally substitutedwith one or more substituents selected from (1-3C)alkyl, halo, hydroxy,(1-3C)alkoxy, aryl or heteroaryl;R¹⁴ is absent, hydrogen, (1-6C)alkyl, halo, hydroxy, (1-3C)alkoxy, arylor heteroaryl; andR¹⁵ is hydrogen or (1-6C)alkyl.

In an embodiment, when one or more of L¹, L² and L³ are absent, then L⁴is CR¹⁴, [BR¹⁵]⁻, (1-3C)alkylene or (2-3C)alkylenylene, said(1-3C)alkylene or (2-3C)alkenylene moieties being optionally substitutedwith one or more substituents selected from (1-3C)alkyl, halo, hydroxy,(1-3C)alkoxy, aryl or heteroaryl. In a further embodiment, when L¹, L²and L³ are absent, then L⁴ is CR¹⁴ or (1-3C)alkylene said (1-3C)alkylenemoiety being optionally substituted with one or more substituentsselected from (1-3C)alkyl, halo, hydroxy, (1-3C)alkoxy, aryl orheteroaryl. In an alternative embodiment, when L⁴ is absent, then L¹, L²and L³ are a bond, (1-3C)alkylene or (2-3C)alkenylene, said(1-3C)alkylene or (2-3C)alkenylene moieties being optionally substitutedwith one or more substituents selected from (1-3C)alkyl, halo, hydroxy,(1-3C)alkoxy, aryl or heteroaryl.

In an embodiment, Q¹, Q² and Q³ are NR¹²R¹³. The nitrogen atom of Q¹, Q²or Q³ has the standard tri-valency of nitrogen. Therefore, as valencypermits, and depending on how many linker groups (L¹, L², L³ and L⁴) anygiven nitrogen atom is bonded to, then either none, one or both of R¹²and R¹³ may be absent. For example, if Q¹ is bonded to L¹, L³ and L⁴,then both of R¹² and R¹³ are absent; if Q¹ is bonded to L¹ and L³, butL⁴ is absent, then one of R¹² and R¹³ is absent; if Q¹ is bonded to L⁴,but L¹ and L³ are absent, then neither of R¹² or R¹³ is absent.

In an embodiment, L⁴ is CR¹⁴ and R¹⁴ is either absent, hydrogen,(1-6C)alkyl, halo, hydroxy, (1-3C)alkoxy, aryl or heteroaryl. When R¹⁴is absent, then L⁴ is C⁻. In other words, the carbon atom bears anegative charge. In an embodiment, L⁴ is CR¹⁴ and R¹⁴ is hydrogen. In anembodiment, L⁴ is [BR¹⁵]⁻ and R¹⁵ is hydrogen or (1-6C)alkyl, such ashydrogen. When L⁴, and therefore as a consequence the ligand Z, bears anegative charge, then to balance the charges in the compound of FormulaI, X¹ or X² is a neutral ligand, for example heterocycloalkyl (such asTHF).

In an embodiment, Z is a ligand of formula IIA or IIB:

wherein Q¹, Q² and Q³ are NR¹²R¹³ or a heteroaryl group containing atleast one nitrogen atom, said heteroaryl group optionally substitutedwith one or more substituents selected from halo, hydroxy, amino, nitro,(1-6C)alkyl, (1-6C)alkoxy, —S-(1-6C)alkyl and (1-6C)haloalkyl;R¹² and R¹³ are independently absent, hydrogen, (1-20C)alkyl, aryl orheteroaryl as valency permits, wherein said (1-20C)alkyl, aryl andheteroaryl groups are optionally substituted with one or moresubstituents selected from halo, hydroxy, amino, nitro, (1-6C)alkyl,(1-6C)haloalkyl and aryl;L¹, L² and L³ are a bond, (1-3C)alkylene or (2-3C)alkenylene, said(1-3C)alkylene or (2-3C)alkenylene moieties being optionally substitutedwith one or more substituents selected from (1-3C)alkyl, halo, hydroxy,(1-3C)alkoxy, aryl or heteroaryl; andL⁴ is CR¹⁴, (1-3C)alkylene or (2-3C)alkylenylene, said (1-3C)alkylene or(2-3C)alkenylene moieties being optionally substituted with one or moresubstituents selected from (1-3C)alkyl, halo, hydroxy, (1-3C)alkoxy,aryl or heteroaryl.

In an embodiment, Z is a ligand of formula IIA and L¹, L² and L³ are(1-3C)alkylene.

In an embodiment, Z is a ligand of formula IIA, Q¹, Q² and Q³ are NR¹²and L¹, L² and L³ are (1-3C)alkylene.

In an embodiment, Z is a ligand of formula IIC:

wherein L¹, L² and L³ are (1-3C)alkylene optionally substituted with oneor more substituents selected from (1-3C)alkyl, halo, hydroxy,(1-3C)alkoxy, aryl or heteroaryl; and each R¹² is independently(1-20C)alkyl optionally substituted with one or more substituentsselected from halo, hydroxy, amino, nitro, (1-6C)alkyl, (1-6C)haloalkyland aryl.

In an embodiment, Z is a ligand of formula IIC, L¹, L² and L³ are(1-3C)alkylene and each R¹² is independently (1-20C)alkyl.

In an embodiment, Z is the ligand of formula IIB:

wherein L⁴ is CR¹⁴, (1-3C)alkylene or (2-3C)alkylenylene, said(1-3C)alkylene or (2-3C)alkenylene moieties being optionally substitutedwith one or more substituents selected from (1-3C)alkyl, halo, hydroxy,(1-3C)alkoxy, aryl or heteroaryl; and Q¹, Q² and Q³ are heteroarylgroups containing at least one nitrogen atom, said heteroaryl groupsbeing optionally substituted with one or more substituents selected fromhalo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl.

In an embodiment, Z is the ligand of formula IIB and L⁴ is CR¹⁴. In apreferred embodiment, R¹⁴ is hydrogen.

In an embodiment, Z is the ligand of formula IIB and Q¹, Q² and Q³ arepyrazolyl or pyridinyl groups optionally substituted with one or moresubstituents selected from halo, (1-6C)alkyl and (1-6C)haloalkyl. In apreferred embodiment, Q¹, Q² and Q³ are pyrazolyl groups substitutedwith one or more (1-6C)alkyl substituents.

In an embodiment, Z is the ligand of formula IIB, L⁴ is CR¹⁴ and Q¹, Q²and Q³ are pyrazolyl or pyridinyl groups optionally substituted with oneor more substituents selected from halo, (1-6C)alkyl and(1-6C)haloalkyl.

In an embodiment, Z is selected from one of the following ligands:

wherein R¹² is (1-20C)alkyl optionally substituted with one or moresubstituents selected from halo, hydroxy, amino, nitro, (1-6C)alkyl,(1-6C)haloalkyl and aryl.

In an embodiment, Z is selected from one of the following ligands:

wherein R¹² is (1-20C)alkyl optionally substituted with one or moresubstituents selected from halo, hydroxy, amino, nitro, (1-6C)alkyl,(1-6C)haloalkyl and aryl.

In an embodiment, Z is selected from one of the following ligands:

wherein R¹² is (1-20C)alkyl optionally substituted with phenyl. In anembodiment, all R¹² substituents are methyl, hexyl, dodecyl or benzyl(i.e. all three R¹² groups are methyl, or all three R¹² groups arehexyl, or all three R¹² groups are dodecyl, or all three R¹² groups arebenzyl). In preferred embodiment, all R¹² substituents are methyl.

The metal, M, is a Group IV transition metal selected from titanium,zirconium and hafnium. In a preferred embodiment, M is titanium.

The ligands X¹ and X² are independently selected from halo, hydrogen, aphosphonate, sulfonate or boronate group, amino, (1-6C)alkyl,(1-6C)alkoxy, aryl, aryloxy and heterocycloalkyl (such as THF), whereinsaid (1-6C)alkyl, (1-6C)alkoxy, aryl and aryloxy groups may beoptionally substituted with one of more groups selected from halo, oxo,hydroxy, amino, nitro, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl,(1-6C)haloalkyl, (1-6C)alkoxy, aryl and Si[(1-4C)alkyl]3. In anembodiment, X¹ and X² are independently selected from halo, hydrogen, aphosphonate, sulfonate or boronate group, amino, (1-6C)alkyl,(1-6C)alkoxy, aryl, aryloxy and heterocycloalkyl. In an embodiment, X¹and X² are independently selected from halo, hydrogen, a phosphonate,(1-6C)alkyl, (1-6C)alkoxy, aryl, aryloxy and heterocycloalkyl. In anembodiment, X¹ and X² are independently selected from halo, (1-6C)alkyland (1-6C)alkoxy. In a preferred embodiment, X¹ and X² are independentlyselected from chloro and methyl. In a further preferred embodiment, X¹and X² are both chloro.

In an embodiment, the compound of formula I is selected from one of thefollowing compounds:

wherein Ar′ is

In an embodiment, the compound of formula I is selected from one of thefollowing compounds:

wherein Ar′ is

The present invention encompasses compounds according to formula I, bothwith an overall net charge of zero, and those compounds that have anoverall net charge other than zero and therefore further comprise asuitable counterion.

Compositions

In a further aspect of the present invention, there is provided acomposition comprising a compound of formula I, as described herein,immobilised on a solid support material.

It will be appreciated that the compound may be immobilised on the solidsupport material by one or more covalent or ionic interactions, eitherdirectly, or via a suitable linking moiety. It will be appreciated thatminor structural modifications resulting from the immobilisation of thecompound on the support material (e.g. loss of one or both of the X¹ andX² groups) are nonetheless within the scope of the invention. Suitably,the solid support material is selected from silica, alumina, zeolite,layered double hydroxide, methylaluminoxane-activated silica,methylaluminoxane-activated layered double hydroxide and solidmethylaluminoxane. Most suitably, the solid support material is solidmethylaluminoxane.

The terms “solid MAO”, “sMAO” and “solid polymethylaluminoxane” are usedsynonymously herein to refer to a solid methylaluminoxane materialhaving the general formula -[(Me)AlO]_(n)—, wherein n is an integer from4 to 50 (e.g. 10 to 50). Any suitable solid methylaluminoxane may beused.

There exist numerous substantial structural and behavioural differencesbetween solid polymethylaluminoxane and other non-solid MAOs. Perhapsmost notably, solid polymethylaluminoxane is distinguished from otherMAOs as it is insoluble in hydrocarbon solvents and so typically acts asa heterogeneous support system for carrying out slurry phase olefinpolymerisations. The solid polymethylaluminoxane useful in thecompositions of the invention are insoluble in toluene and hexane.

In an embodiment, the aluminium content of the solidpolymethylaluminoxane falls within the range of 36-41 wt %.

The solid polymethylaluminoxane useful as part of the present inventionis characterised by extremely low solubility in toluene and n-hexane. Inan embodiment, the solubility in n-hexane at 25° C. of the solidpolymethylaluminoxane is 0-2 mol %. Suitably, the solubility in n-hexaneat 25° C. of the solid polymethylaluminoxane is 0-1 mol %. Moresuitably, the solubility in n-hexane at 25° C. of the solidpolymethylaluminoxane is 0-0.2 mol %. Alternatively, or additionally,the solubility in toluene at 25° C. of the solid polymethylaluminoxaneis 0-2 mol %. Suitably, the solubility in toluene at 25° C. of the solidpolymethylaluminoxane is 0-1 mol %. More suitably, the solubility intoluene at 25° C. of the solid polymethylaluminoxane is 0-0.5 mol %. Thesolubility in solvents can be measured by the method described inJP-B(KOKOKU)-H07 42301.

Olefin Polymerisation Processes

In a further aspect of the present invention, there is provided aprocess for the polymerisation of at least one olefin, the processcomprising the step of contacting the at least one olefin with acompound or composition of the invention, as described herein.

In an embodiment, the at least one olefin is at least one (2-10C)alkene.

In an embodiment, the at least one olefin is at least one α-olefin.

In an embodiment, the at least one olefin is ethene and optionally oneor more other (3-10C)alkenes. When the optional one or more other(3-10C)alkenes is present, the polymerisation process is acopolymerisation process. Suitable optional one or more other(3-10C)alkenes include 1-hexene, styrene and methyl methacrylate.

In an embodiment, the polymerisation process is a homopolymerisationprocess and the at least one olefin is ethene.

In an embodiment, the process is conducted in a solvent selected fromtoluene, hexane and heptane.

In an embodiment, the process is conducted for a period of 1 minute to96 hours. Suitably, the process is conducted for a period of 5 minutesto 72 hours, such as 5 minutes to 4 hours.

In an embodiment, the process is conducted at a pressure of 0.9 to 10bar. Suitably, the process is conducted at a pressure of 1.5 to 3 bar.

In an embodiment, the process is conducted at a temperature of 15 to120° C. Suitably, the process is conducted at a temperature of 40 to100° C. In an embodiment, the process is conducted at a temperature of15 to 30° C. In an alternative embodiment, the polymerisation processcomprises the step of contacting the at least one olefin with acomposition comprising a compound of the invention immobilised on asolid support material, at a temperature of either 50° C., 60° C. or 70°C.

In an embodiment, the process is conducted in the presence of aco-catalyst. Suitably, the co-catalyst is one or more organoaluminiumcompounds. More suitably, the one or more organoaluminium compounds areselected from alkylaluminoxane (e.g. methylaluminiumoxane),triisobutylaluminium and triethylaluminium.

The person skilled in the art will realise that further additives mayoptionally be included in the olefin polymerisation process, such asadditional scavengers, stabilisers or carriers.

Polymerisation processes according to this invention may be undertakenas slurry phase or solution phase processes. The use of a compoundaccording to formula (I) immobilised on a solid support material ispreferred for slurry phase processes, whereas a non-supported catalystcompound according to formula (I) is preferred for solution phaseprocesses.

In a further aspect, the invention provides a polyolefin directlyobtained by, obtained by or obtainable by a process as described herein.The catalyst compounds according to formula I, when used in a process asdescribed herein, give rise to polyolefins (such as polyethylenes) withhigh molecular weight and/or low polydispersity (as demonstrated by arelatively low M_(w)/M_(n) value). In an embodiment, the polyolefin hasan average molecular weight greater than 1×10⁶ g/mol, such as greaterthan 2×10⁶ g/mol, preferably greater than 3×10⁶ g/mol. In an embodiment,the polyolefin has a M_(w)/M_(n) value less than 15, such as less than10, preferably less than 5. In an embodiment, the polyolefin has anaverage molecular weight greater than 1×10⁶ g/mol and a M_(w)/M_(n)value less than 15. In a further embodiment, the polyolefin has anaverage molecular weight greater than 2×10⁶ g/mol and a M_(w)/M_(n)value less than 10. In a preferred embodiment, the polyolefin has anaverage molecular weight greater than 3×10⁶ g/mol and a M_(w)/M_(n)value less than 5.

The following numbered statements 1-48 are not claims, but insteaddescribe various aspects and embodiments of the invention:

-   1. A compound of Formula I:

-   -   wherein:    -   M is selected from titanium, zirconium and hafnium;    -   X¹ and X² are independently selected from halo, hydrogen, a        phosphonate, sulfonate or boronate group, amino, (1-6C)alkyl,        (1-6C)alkoxy, aryl, aryloxy and heterocycloalkyl (such as THF),        wherein said (1-6C)alkyl, (1-6C)alkoxy, aryl and aryloxy groups        may be optionally substituted with one of more groups selected        from halo, oxo, hydroxy, amino, nitro, (1-6C)alkyl,        (2-6C)alkenyl, (2-6C)alkynyl, (1-6C)haloalkyl, (1-6C)alkoxy,        aryl and Si[(1-4C)alkyl]₃;    -   Y is BR¹R²    -   Z is a polydentate ligand coordinated to M by at least 2 donor        atoms Q, wherein each    -   Q is independently selected from N, O, S and P;    -   R¹ and R² are independently selected from NR³R⁴, OR⁵, SR⁶ and        CR⁷R⁸R⁹;    -   R³, R⁴, R⁵, R⁶, R⁷, R⁸ and R⁹ are independently selected from        hydrogen, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, aryl and        heteroaryl, wherein said (1-6C)alkyl, (2-6C)alkenyl,        (2-6C)alkynyl, aryl and heteroaryl groups are optionally        substituted with one or more substituents selected independently        from halo, hydroxy, amino, nitro, (1-6C)alkyl and        (1-6C)haloalkyl;    -   or R¹ and R² are linked, such that when taken in combination        with the boron atom to which they are attached, they form a        group:

-   -   wherein ring A is a carbocyclic or heterocyclic ring, optionally        substituted with one or more substituents selected independently        from halo, hydroxy, amino, (1-6C)alkyl, (1-6C)alkoxy,        (1-6C)haloalkyl, aryl and heteroaryl, wherein said aryl and        heteroaryl groups are optionally substituted with one or more        substituents selected independently from halo, hydroxy, amino,        nitro, (1-6C)alkyl and (1-6C)haloalkyl.

-   2. The compound according to statement 1, wherein R¹ and R² are    independently selected from NR³R⁴, OR⁵ and SR⁶.

-   3. The compound according to statement 1, wherein R¹ and R² are both    NR³R⁴.

-   4. The compound according to statement 1, wherein R¹ and R² are    linked, such that when taken in combination with the boron atom to    which they are attached, they form a group:

-   -   wherein X is a heteroatom chosen from NR¹⁰, O and S;    -   the heterocyclic ring A is optionally substituted with one or        more substituents selected independently from halo, hydroxy,        amino, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)haloalkyl, aryl and        heteroaryl, wherein said aryl and heteroaryl groups are        optionally substituted with one or more substituents selected        independently from halo, hydroxy, amino, nitro, (1-6C)alkyl and        (1-6C)haloalkyl; and    -   R¹⁰ is (1-6C)alkyl, aryl or heteroaryl, wherein said        (1-6C)alkyl, aryl and heteroaryl groups are optionally        substituted with one or more substituents selected independently        from halo, hydroxy, amino, nitro, (1-6C)alkyl and        (1-6C)haloalkyl.

-   5. The compound according to statement 1, wherein R¹ and R² are    linked, such that when taken in combination with the boron atom to    which they are attached, they form a group:

-   -   wherein the heterocyclic ring A is optionally substituted with        one or more substituents selected independently from halo,        hydroxy, amino, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)haloalkyl, aryl        and heteroaryl, wherein said aryl and heteroaryl groups are        optionally substituted with one or more substituents selected        independently from halo, hydroxy, amino, nitro, (1-6C)alkyl and        (1-6C)haloalkyl; and    -   each R¹⁰ is independently (1-6C)alkyl, aryl or heteroaryl,        wherein said (1-6C)alkyl, aryl and heteroaryl groups are        optionally substituted with one or more substituents selected        independently from halo, hydroxy, amino, nitro, (1-6C)alkyl and        (1-6C)haloalkyl.

-   6. The compound according to statement 1, wherein Y is selected from    one of the following groups:

-   -   wherein each R¹⁰ is independently (1-6C)alkyl, aryl or        heteroaryl, wherein said (1-6C)alkyl, aryl and heteroaryl groups        are optionally substituted with one or more substituents        selected independently from halo, hydroxy, amino, nitro,        (1-6C)alkyl and (1-6C)haloalkyl.    -   7. The compound according to statements 4 to 6, wherein R¹⁰ is        an aryl group optionally substituted with one or more        substituents selected independently from (1-6C)alkyl and        (1-6C)haloalkyl.    -   8. The compound according to statements 4 to 7, wherein R¹⁰ is        the following group:    -   wherein R¹¹ is (1-6C)alkyl.

-   9. The compound according to statement 8, wherein both R¹¹ are    isopropyl.-   10. The compound according to statements 4 to 6, wherein R¹⁰ is    (1-6C)alkyl.-   11. The compound according to statement 10, wherein R¹⁰ is methyl,    ethyl, propyl or isopropyl.-   12. The compound according to statements 4 to 6, wherein both R¹⁰    are methyl.-   13. The compound according to statements 4 to 6, wherein both R¹⁰    are isopropyl.-   14. The compound according to any one of statements 1 to 13, wherein    Z is a tri- or tetra-dentate ligand coordinated to M by 3-4 donor    atoms Q.-   15. The compound according to statement 14, wherein Z is a    tridentate ligand coordinated to M by 3 donor atoms Q.-   16. The compound according to statement 14 or statement 15, wherein    each donor atom Q is N.-   17. The compound according to statements 1 to 16, wherein Z is the    ligand according to formula II:

-   -   wherein Q¹, Q² and Q³ are NR¹²R¹³ or a heteroaryl group        containing at least one nitrogen atom, said heteroaryl group        optionally substituted with one or more substituents selected        from halo, hydroxy, amino, nitro, (1-6C)alkyl, (1-6C)alkoxy,        —S-(1-6C)alkyl and (1-6C)haloalkyl;    -   R¹² and R¹³ are independently absent, hydrogen, (1-20C)alkyl,        aryl or heteroaryl as valency permits, wherein said        (1-20C)alkyl, aryl and heteroaryl groups are optionally        substituted with one or more substituents selected from halo,        hydroxy, amino, nitro, (1-6C)alkyl, (1-6C)haloalkyl and aryl;    -   L¹, L² and L³ are absent, a bond, (1-3C)alkylene or        (2-3C)alkenylene, said (1-3C)alkylene or (2-3C)alkenylene        moieties being optionally substituted with one or more        substituents selected from (1-3C)alkyl, halo, hydroxy,        (1-3C)alkoxy, aryl or heteroaryl;    -   L⁴ is absent, CR¹⁴, [BR¹⁵]⁻, (1-3C)alkylene or        (2-3C)alkylenylene, said (1-3C)alkylene or (2-3C)alkenylene        moieties being optionally substituted with one or more        substituents selected from (1-3C)alkyl, halo, hydroxy,        (1-3C)alkoxy, aryl or heteroaryl;    -   R¹⁴ is absent, hydrogen, (1-6C)alkyl, halo, hydroxy,        (1-3C)alkoxy, aryl or heteroaryl; and    -   R¹⁵ is hydrogen or (1-6C)alkyl.

-   18. The compound according to statement 17, wherein Z is a ligand of    formula IIA or IIB:

-   -   wherein L¹, L² and L³ are a bond, (1-3C)alkylene or        (2-3C)alkenylene, said (1-3C)alkylene or (2-3C)alkenylene        moieties being optionally substituted with one or more        substituents selected from (1-3C)alkyl, halo, hydroxy,        (1-3C)alkoxy, aryl or heteroaryl; and    -   L⁴ is CR¹⁴, (1-3C)alkylene or (2-3C)alkylenylene, said        (1-3C)alkylene or (2-3C)alkenylene moieties being optionally        substituted with one or more substituents selected from        (1-3C)alkyl, halo, hydroxy, (1-3C)alkoxy, aryl or heteroaryl.

-   19. The compound according to statement 18, wherein Z is the ligand    of formula IIC:

-   -   wherein each R¹² is independently (1-20C)alkyl optionally        substituted with one or more substituents selected from halo,        hydroxy, amino, nitro, (1-6C)alkyl, (1-6C)haloalkyl and aryl.

-   20. The compound according to statement 18, wherein Z is the ligand    of formula IIB:

-   -   wherein    -   Q¹, Q² and Q³ are heteroaryl groups containing at least one        nitrogen atom, said heteroaryl groups being optionally        substituted with one or more substituents selected from halo,        hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl.

-   21. The compound according to statement 20, wherein L⁴ is CR¹⁴.

-   22. The compound according to statement 21, wherein R¹⁴ is hydrogen.

-   23. The compound according to statements 20 to 22, wherein Q¹, Q²    and Q³ are pyrazolyl or pyridinyl groups optionally substituted with    one or more substituents selected from halo, (1-6C)alkyl and    (1-6C)haloalkyl.

-   24. The compound according to statements 1 to 13, wherein Z is    selected from one of the following ligands:

-   -   wherein R¹² is (1-20C)alkyl optionally substituted with one or        more substituents selected from halo, hydroxy, amino, nitro,        (1-6C)alkyl, (1-6C)haloalkyl and aryl.

-   25. The compound according to statements 1 to 13, wherein Z is    selected from one of the following ligands:

-   -   wherein R¹² is (1-20C)alkyl optionally substituted with one or        more substituents selected from halo, hydroxy, amino, nitro,        (1-6C)alkyl, (1-6C)haloalkyl and aryl.

-   26. The compound according to statements 1 to 13, wherein Z is    selected from one of the following polydentate ligands:

wherein R¹² is (1-20C)alkyl optionally substituted with phenyl.

-   27. The compound according to statement 26, wherein all R¹²    substituents are methyl, hexyl, dodecyl or benzyl.-   28. The compound according to statement 27, wherein all R¹²    substituents are methyl.-   29. The compound according to any one of statements 1 to 28, wherein    M is titanium.-   30. The compound according to any one of statements 1 to 29, wherein    X¹ and X² are independently selected from halo, hydrogen, a    phosphonate, sulfonate or boronate group, amino, (1-6C)alkyl,    (1-6C)alkoxy, aryl, aryloxy and heterocycloalkyl.-   31. The compound according to any one of statements 1 to 29, wherein    X¹ and X² are independently selected from halo, (1-6C)alkyl and    (1-6C)alkoxy.-   32. The compound according to any one of statements 1 to 29, wherein    X¹ and X² are independently selected from chloro and methyl.-   33. The compound according to any one of statements 1 to 29, wherein    X¹ and X² are both chloro.-   34. A composition comprising a compound according to any one of    statements 1 to 33 immobilised on a solid support material.-   35. The composition according to statement 34, wherein the solid    support material is selected from silica, alumina, zeolite, layered    double hydroxide, methylaluminoxane-activated silica,    methylaluminoxane-activated layered double hydroxide and solid    methylaluminoxane.-   36. The composition according to statement 34, wherein the solid    support material is solid methylaluminoxane.-   37. The compound according to any one of statements 1 to 33, or the    composition according to any one of statements 34 to 36, which when    used as a catalyst in the polymerisation of ethylene is capable of    producing polyethylene with a mass average molecular weight (M_(w))    of greater than 1.1×10⁶ g/mol, such as greater than 1.5×10⁶ g/mol,    or greater than 2.5×10⁶ g/mol.-   38. The compound according to any one of statements 1 to 33, or the    composition according to any one of statements 34 to 36, which when    used as a catalyst in the polymerisation of ethylene is capable of    producing polyethylene with a polydispersity index (M_(w)/M_(n)) of    less than 10, such as less than 7, or less than 5.-   39. The compound according to any one of statements 1 to 33, or the    composition according to any one of statements 34 to 36, which when    used as a catalyst in the polymerisation of ethylene is capable of    producing polyethylene with a mass average molecular weight (M_(w))    of greater than 1.1×10⁶ g/mol and a polydispersity index    (M_(w)/M_(n)) of less than 10, such as a mass average molecular    weight (M_(w)) of greater than 1.5×10⁶ g/mol and a polydispersity    index (M_(w)/M_(n)) of less than 7, or a mass average molecular    weight (M_(w)) of greater than 2.5×10⁶ g/mol and a polydispersity    index (M_(w)/M_(n)) of less than 5.-   40. The compound or the composition according to any one of    statements 37 to 39, wherein the catalyst is supported on solid    methylaluminoxane and the ethylene polymerisation is carried out    under the following slurry-phase conditions: 10 mg of supported    catalyst is heated with 150 mg of triisobutylaluminium in 50 ml of    hexane at 60° C. or 70° C. under 3 bar dynamic pressure of ethylene    for 15 minutes.-   41. A process for the polymerisation of at least one olefin, the    process comprising the step of contacting the at least one olefin    with a compound according to any one of statements 1 to 33, or a    composition according to any one of statements 34 to 36.-   42. The process according to statement 41, wherein the at least one    olefin is at least one (2-10C)alkene.-   43. The process according to statement 41 or statement 42, wherein    the at least one olefin is at least one α-olefin.-   44. The process according to statement 41, wherein the at least one    olefin is ethene and optionally one or more other (3-10C)alkenes    (e.g. 1-hexene, styrene and/or methyl methacrylate).-   45. The process according to statement 41, wherein the at least one    olefin is ethene.-   46. The process according to any one of statements 41 to 45, wherein    the process is conducted in the presence of a co-catalyst.-   47. The process of statement 46, wherein the co-catalyst is one or    more organoaluminium compounds.-   48. The process of statement 47, wherein the one or more    organoaluminium compounds are selected from methylaluminoxane,    triisobutylaluminium and triethylaluminium.

EXAMPLES Materials and Methods

All manipulations were carried out using standard Schlenk line ordry-box techniques under an atmosphere of argon or dinitrogen. Solventswere either degassed by sparging with dinitrogen and dried by passingthrough a column of the appropriate drying agent (Pangborn et al.,Organometallics, 1996, 15, 1518-1520) or refluxed over sodium (toluene),potassium (THF), Na/K alloy (Et₂O) or CaH₂ (pyridine) and distilled. Alldry solvents were stored under nitrogen and degassed by severalfreeze-pump-thaw cycles.

Me₃[6]aneN₃ (1,3,5-trimethyl-1,3,5-triazinane) and Me₃[9]aneN₃(1,4,7-trimethyl-1,4,7-triazonane) were prepared according to Köhn etal., Inorg. Chem., 1997, 36, 6064-6069 and WO1994/000439. Hex₃[6]aneN₃(1,3,5-trihexyl-1,3,5-triazinane) and DD₃[6]aneN₃(1,3,5-tridodecyl-1,3,5-triazinane) were prepared according to Hoerr etal., J. Am. Chem. Soc., 1956, 78, 4667-4670. Bn₃[6]aneN₃(1,3,5-tribenzyl-1,3,5-triazinane) was prepared according to Köhn etal., Eur. J. Inorg. Chem., 2005, 4, 3217-3223. Me₄DACH(N,N,1,4,6-pentamethyl-1,4-diazepan-6-amine) was prepared according toGe et al., Chem. Commun., 2006, 3320-3322. HC(Me₂pz)₃(tris(3,5-dimethyl-1H-pyrazol-1-yl)methane) was prepared according toReger et al., J. Organomet. Chem., 2000, 607, 120-128.

¹H, ¹³C{¹H} and ¹¹B{¹H} spectra were recorded on a Bruker Ascend 400 NMRspectrometer, a Bruker Avance III 500 NMR spectrometer or on a BrukerAVC 500 spectrometer fitted with a ¹³C cryoprobe. Unless otherwisestated, all NMR spectra were recorded at 298 K. ¹H and ¹³C{¹H} andspectra were referenced internally to residual protio-solvent (¹H) orsolvent (¹³C) resonances and are reported relative to tetramethylsilane(δ=0 ppm). ¹¹B NMR spectra were referenced externally to Et₂O.BF₃.Assignments were confirmed as necessary with the use of two dimensional¹H-¹H and ¹³C-¹H correlation experiments. Chemical shifts are quoted inδ (ppm) and coupling constants in Hz. Elemental analysis was carried outto confirm the overall composition of the materials.

Synthesis of Catalyst Precursors Intermediate 1

A convenient large-scale and high-yielding synthesis of the borylamineH₂NB(NAr′CH)₂ (Intermediate 1) was reported by Jones and co-workers(Hadlington et al., Chem. Commun., 2016, 52, 1717-1720). Ammonia gas wasbubbled through a hexane solution of the 1,3,2-diazaborolyl bromideprecursor BrB(NAr′CH)₂ (2). The resulting borylamine 1 was easilyseparated from the NH₄Br by-product by filtration, to isolate 1 in 75%yield. The 1,3,2-diazaborolyl bromide precursor itself is preparedultimately from the commercially available materials glyoxal, H₂NAr′ andBBr₃ in the sequence of steps shown above and as described in theliterature (Jafarpour et al., J. Organomet. Chem., 2000, 606, 49-54;Segawaki et al., J. Am. Chem. Soc., 2008, 130, 16069-16079).

Intermediate 3

According to a literature preparation (Weber et al., Dalton. Trans.,2013, 42, 2266-2281), 1,2-phenylenediamine was reacted with2-iodopropane, and then BBr₃ (in the presence of CaH₂) to form thebromoborane BrB(N^(i)Pr)₂C₆H₄ (4) in a 44% yield. Slow addition of ahexane solution of 4 to liquid ammonia at −78° C. allowed controlledaccess to the novel borylamine H₂NB(N^(i)Pr)₂C₆H₄ (Intermediate 3) as acolourless oil in 60% yield, without the concomitant formation of thebis(boryl)amine impurity observed with reaction with gaseous ammonia(Clough et al., J. Am. Chem. Soc., 2017, 139, 11165-11183).

Intermediate 5

The C₆H₄(NHMe)₂ precursor was prepared via tosylation, methylation andsubsequent deprotection with concentrated sulfuric acid according toliterature methods (N. Proust, J. C. Gallucci and L. A. Paquette, J.Org. Chem., 2009, 74, 2897-2900; T. Vlaar, R. C. Cioc, P. Mampuys, B. U.W. Maes, R. V. A. Orru and E. Ruijter, Angew. Chem. Int. Ed., 2012, 51,13058-13061).

To a mixture of BBr₃ (6.40 mL, 56.4 mmol) and CaH₂ (7.91 g, 188 mmol) inhexane (120 mL) was added a solution of 1,2-C₆H₄(NHMe)₂ (6.40 g, 47.0mmol) in hexane (120 mL) dropwise, at 0° C. The mixture was allowed towarm to RT, and then stirred for 16 h. After this time, the mixture wasfiltered, then the remaining white solid was extracted with Et₂O (3×60mL). The Et₂O was removed from the extracts under reduced pressure, andthe product dried in vacuo to leave Intermediate 5 as a brown, waxysolid. Yield: 4.30 g (41%). ¹H NMR (C₆D₆, 400.1 MHz): δ 7.05 (2H, m,3,4-C₆H₄), 6.75 (2H, m, 2,5-C₆H₄), 2.88 (6H, s, NMe) ppm. ¹³C{¹H} NMR(C₆D₆, 100.6 MHz): δ 137.8 (1,6-C₆H₄), 119.9 (3,4-C₆H₄), 108.9(2,5-C₆H₄), 29.2 (NMe) ppm. ¹¹B{¹H} NMR (C₆D₆, 128.4 MHz): δ 23.9 ppm.IR (NaCl plates, Nujol mull, cm⁻¹): 2114 (w), 1907 (w), 1862 (w), 1816(w), 1745 (w), 1608 (s), 1290 (s), 1233 (s), 1124 (s), 1071 (s), 909(m), 807 (m), 734 (s), 615 (m), 552 (m). Anal. found (calcd. forC₃H₁₀BBrN₂): C, 42.58 (42.73); H, 4.34 (4.48); N, 12.54 (12.46)%.

Intermediate 6

A toluene solution (120 mL) of BrB(NMe)₂C₆H₄ (Intermediate 5, 4.30 g,19.1 mmol) was added in 1 mL portions to liquid NH₃ (30 mL) at −78° C.,then the mixture allowed to warm to RT over 4 h, during which time theexcess NH₃ boiled off was released through an oil bubbler with N₂ flow.The mixture was warmed to 50° C., upon which further NH₃ boil-off wasobserved. The mixture was then filtered and the volatiles removed fromthe filtrate under reduced pressure, to leave Intermediate 6 as a whitepowder, which was then dried in vacuo. Yield: 2.55 g (83%). ¹H NMR(C₆D₆, 400.1 MHz): δ 7.09 (2H, m, 3,4-C₆H₄), 6.75 (2H, m, 2,5-C₆H₄),2.64 (6H, s, NMe), 1.50 (2H, br. s, NH₂) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6MHz): δ 130.5 (1,6-C₆H₄), 118.3 (3,4-C₆H₄), 106.5 (2,5-C₆H₄), 29.2 (NMe)ppm. ¹¹B{¹H} NMR (C₆D₆, 128.4 MHz): δ 24.7 ppm. IR (NaCl plates, Nujolmull, cm⁻¹): 3454 (s), 3362 (s), 3196 (w), 2093 (w), 1883 (w), 1831 (w),1716 (w), 1683 (w), 1606 (s), 1565 (m), 1502 (s), 1309 (s), 1235 (m),1130 (m), 1049 (m), 891 (m), 860 (m), 735 (s), 636 (m). Anal. found(calcd. for C₈H₁₂BN₃): C, 59.57 (59.68); H, 7.39 (7.51); N, 25.87(26.10)%.

Precursor 7

To a solution of Ti(NMe₂)₂Cl₂ (1.36 g, 6.58 mmol) in toluene (10 mL) wasslowly added a solution of H₂NB(NAr′CH)₂ (Intermediate 1, 2.52 g, 6.25mmol) in toluene (10 mL), at −78° C. The mixture was allowed to warm toRT, upon which it became a red/brown slurry. After stirring for 30 mins,all solids had dissolved, leaving a deep red solution, which was stirredat RT for a further 2.5 h. The volatiles were then removed under reducedpressure to leave a red-brown, waxy solid. The product was triturated inhexane, yielding Intermediate 7 as an orange-brown powder. Yield: 3.01 g(79%). Diffraction-quality crystals were grown from a saturated hexanesolution at room temperature. ¹H NMR (C₆D₆, 400.1 MHz): δ 7.13 (6H,overlapping 2×m, m- and p-C₆ H ₃ ^(i)Pr₂), 5.73 (2H, s, NCH), 3.53 (4H,sept., ³J=6.9 Hz, CHMeMe), 2.67 (2H, sept., ³J=6.1 Hz, NHMe₂), 1.92(12H, d, ³J=6.1 Hz, NHMe ₂), 1.56 (12H, d, ³J=6.9 Hz, CHMeMe), 1.24(12H, d, ³J=6.9 Hz, CHMeMe) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6 MHz): δ 146.8(i-C ₆H₃ ^(i)Pr₂), 140.2 (o-C ₆H₃ ^(i)Pr₂), 127.2 (p-C ₆H₃ ^(i)Pr₂),123.3 (m-C ₆H₃ ^(i)Pr₂), 115.5 (NCH), 40.0 (NHMe ₂), 28.4 (CHMeMe), 24.2(CHMeMe), 24.0 (CHMeMe) ppm. ¹¹B{¹H} NMR (C₆D₆, 128.4 MHz): δ 14.2 ppm.IR (NaCl plates, Nujol mull, cm⁻¹): 3289 (w, non-bridging N—H), 3277 (w,hydrogen bonded N—H), 1586 (m), 1260 (w), 1180 (w), 1076 (w), 1025 (m),983 (m), 890 (m), 798 (m), 686 (w), 652 (m). IR (NaCl cell, CH₂Cl₂, v(N—H), cm⁻¹): 3288. Anal. found (calcd. for C₃₀H₅₀BCl₂N₅Ti): C, 58.95(59.04); H, 8.18 (8.26); N, 11.37 (11.47)%.

Precursor 8

To a solution of Ti(NMe₂)₂Cl₂ (2.00 g, 0.01 mol) in toluene (50 mL) wasadded a solution of H₂NB(N^(i)Pr)₂C₆H₄ (Intermediate 3, 2.10 g, 0.01mol) in toluene (25 mL). The reaction was left to stir for 24 hours atRT. The solvent was removed in vacuo, then the solid washed with toluene(3×10 mL) and dried in vacuo, yielding Precursor 8 as a yellow-brownsolid. Yield: 3.20 g (65%). Diffraction-quality crystals were grown froma concentrated hexane solution at RT. ¹H NMR (C₆D₆, 400.1 MHz): δ 7.05(4H, m, J=2.4 Hz, 2,3,4,5-C₆ H ₄), 4.70 (2H, sept., ³J=6.9 Hz, CHMe)₂,2.82 (2H, sept, ³J=6.2 Hz, NHMe₂, 2.29 (12H, d, ³J=6.1 Hz, NHMe ₂, 1.62(12H, d, ³J=6.8 Hz, CHMe ₂). ¹³C{¹H} NMR (C₆D₆, 100.6 MHz): 134.5(1,6-C₆H₄), 118.2 (2,5-C₆H₄), 109.9 (3,4-C₆H₄), 44.5 (CHMe)₂), 40.6(NHMe ₂), 22.7 (CHMe ₂). ¹¹B{¹H} NMR (C₆D₆, 128.4 MHz): δ 14.4 ppm. IR(NaCl plates, Nujol mull, cm⁻¹): 3257 (m, N—H), 2851 (m), 2726 (w), 2360(w), 1594 (m), 1463.34 (s), 1376 (s), 1338 (m), 1290 (m), 1261 (w), 1133(w), 1017 (m), 993 (m), 892 (s), 801 (m), 747 (m), 722 (m), 659 (w).Anal. found (calcd. for C₁₆H₃₂BCl₂N₅Ti): C, 45.16 (45.32); H, 7.48(7.61); N, 16.37 (16.52)%.

Precursor 9

To a mixture of Ti(NMe₂)₂Cl₂ (1.61 g, 7.76 mmol) and H₂NB(NMe)₂C₆H₄(Intermediate 6, 1.25 g, 7.76 mmol) in a Schlenk tube was added toluene(30 mL) at −78° C. The mixture was allowed to warm to RT and stirred for1 h. After this time, the volatiles were removed under reduced pressure,then the yellow solid washed with hexane (3×15 mL) and dried in vacuo,to yield Precursor 9 as a bright yellow powder. Yield: 2.17 g (76%). ¹HNMR (CD₂Cl₂, 400.1 MHz): δ 6.85 (2H, m, 3,4-C₆H₄), 6.77 (2H, m,2,5-C₆H₄), 3.61 (2H, br. m, NHMe₂), 3.32 (6H, s, B(NMe)₂), 2.79 (12H, d,³J=6.2 Hz, NHMe ₂) ppm. ¹³C{¹H} NMR (CD₂Cl₂, 100.6 MHz): δ 136.8(1,6-C₆H₄), 118.9 (3,4-C₆H₄), 107.9 (2,5-C₆H₄), 41.8 (NHMe₂), 28.9(B(NMe)₂) ppm. ¹¹B{¹H} NMR (CD₂Cl₂, 128.4 MHz): δ 14.5 ppm. IR (NaClplates, Nujol mull, cm¹): 3245 (s, non-bridging N—H), 3238 (s,hydrogen-bonded N—H), 1601 (m), 1504 (w), 1434 (s), 1419 (s), 1314 (s),1231 (w), 1211 (w), 1132 (m), 1121 (m), 1059 (w), 1003 (m), 897 (s), 788(w), 744 (s), 645 (m). Anal. found (calcd. for Cl₂H₂₄BCl₂N₅Ti): C, 39.25(39.17); H, 6.36 (6.58); N, 18.79 (19.03)%.

Precursor 10

To a Schlenk flask containing Ti{NB(NAr′CH)₂}Cl₂(NHMe₂)₂ (Precursor 7,3.0 g, 4.92 mmol) was added pyridine (5 mL). The brown solution wasstirred at RT for 10 mins, and then the volatiles removed under reducedpressure to give a yellow-brown waxy solid, which was triturated inhexane (10 mL) to yield Precursor 10 as a bright yellow powder. Yield:3.30 g (89%). Diffraction-quality crystals were grown from a saturatedhexane solution at 5° C. ¹H NMR (C₆D₆, 400.1 MHz): δ 8.72 (4H, d, ³J=4.9Hz, 2,6-py cis to NB(NAr′CH)₂), 8.63 (2H, br. m, 2,6-py trans toNB(NAr′CH)₂), 7.13-7.06 (6H, overlapping 2×m, m- and p-C₆ H ₃ ^(i)Pr₂),6.89 (1H, br. m, 4-py trans to NB(NAr′CH)₂), 6.77 (2H, t, ³J=7.6 Hz,4-py cis to NB(NAr′CH)₂), 6.57 (2H, br. m, 3,5-py trans to NB(NAr′CH)₂),6.40 (4H, m, 3,5-py cis to NB(NAr′CH)₂), 5.70 (2H, s, NCH), 3.63 (4H,sept., ³J=6.9 Hz, CHMeMe), 1.50 (12H, d, ³J=6.9 Hz, CHMeMe), 1.26 (12H,d, ³J=6.9 Hz, CHMeMe) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6 MHz): δ 151.6(2,6-py cis to NB(NAr′CH)₂), 150.8 (2,6-py trans to NB(NAr′CH)₂), 147.3(o-C ₆H₃ ^(i)Pr₂), 140.9 (i-C ₆H₃ ^(i)Pr₂), 137.3 (4-py cis toNB(NAr′CH)₂), 135.7 (4-py trans to NB(NAr′CH)₂), 127.4 (p-C ₆H₃^(i)Pr₂), 123.7 (3,5-py cis to NB(NAr′CH)₂), 123.6 (m-C ₆H₃ ^(i)Pr₂),123.4 (3,5-py trans to NB(NAr′CH)₂), 116.2 (NCH), 28.8 (CHMeMe), 24.5(CHMeMe), 24.3 (CHMeMe) ppm. ¹¹B{¹H} NMR (C₆D₆, 128.4 MHz): δ 13.8 ppm.IR (NaCl plates, Nujol mull, cm⁻¹): 3072 (w), 1606 (s), 1219 (s), 1117(m), 1102 (m), 1073 (m), 1043 (m), 1015 (m), 896 (s), 802 (m), 710 (w),698 (w), 686 (m), 667 (w), 646 (m), 638 (w), 616 (w). Anal. found(calcd. for C₄₁H₅₁BCl₂N₆Ti): C, 64.84 (65.01); H, 6.86 (6.79); N, 10.94(11.09)%.

Synthesis of Example Borylimide Catalysts Example 1

To a solution of Ti{NB(NAr′CH)₂}Cl₂(NHMe₂)₂ (Precursor 7, 0.50 g, 0.819mmol) in toluene (15 mL) was added Me₃[9]aneN₃ (159 μL, 0.819 mmol) viamicrosyringe at RT. The mixture was heated to 45° C. and then stirredfor 16 h, after which time it had become an orange solution. Thevolatiles were removed under reduced pressure, and the yellow solidwashed with hexane (2×8 mL), then dried in vacuo, leaving Example 1 as apale yellow powder. Yield: 0.427 g (75%). ¹H NMR (C₆D₆, 400.1 MHz): δ7.29 (6H, overlapping 2×m, m- and p-C₆ H ₃ ^(i)Pr₂), 5.89 (2H, s, NCH),3.69 (4H, sept., ³J=6.9 Hz, CHMeMe), 2.74 (2H, m, NCH₂), 2.59 (6H, s,NMe cis to NB(NAr′CH)₂), 2.38 (2H, m, NCH₂), 2.28 (3H, s, NMe trans toNB(NAr′CH)₂), 2.24 (2H, m, NCH₂), 1.74 (2H, m, NCH₂), 1.61 (12H, d,³J=6.9 Hz, CHMeMe), 1.52 (2H, m, NCH₂), 1.38 (2H, m, NCH₂), 1.31 (12H,d, ³J=6.9 Hz, CHMeMe) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6 MHz): δ 147.1 (o-C₆H₃ ^(i)Pr₂), 141.3 (i-C ₆H₃ ^(i)Pr₂), 127.1 (p-C ₆H₃ ^(i)Pr₂), 123.4(m-C ₆H₃ ^(i)Pr₂), 117.0 (NCH), 56.7 (NCH₂), 56.6 (NCH₂), 54.0 (NCH₂),53.7 (NMe cis to NB(NAr′CH)₂), 48.9 (NMe trans to NB(NAr′CH)₂), 29.0(CHMeMe), 26.4 (CHMeMe), 23.5 (CHMeMe) ppm. ¹¹B{¹H} NMR (C₆D₆, 128.4MHz): δ 14.0 ppm. IR (NaCl plates, Nujol mull, cm⁻¹): 2359 (w), 2343(w), 1701 (w), 1586 (w), 1497 (m), 1422 (m), 1399 (s), 1325 (s), 1274(m), 1226 (w), 1206 (w), 1178 (w), 1115 (m), 1069 (s), 1005 (s), 994(m), 937 (m), 892 (s), 804 (m), 762 (s), 751 (m), 698 (w), 670 (m), 660(s), 621 (w), 584 (m). EI-MS: m/z=690 [M]⁺ (14%). Anal. found (calcd.for C₃₅H₅₇BCl₂N₆Ti): C, 60.62 (60.80); H, 8.46 (8.31); N, 12.04(12.15)%.

Example 2

To a solution of Ti{NB(NAr′CH)₂}Cl₂(Me₃[9]aneN₃) (Example 1, 0.20 g,0.289 mmol) in toluene (10 mL) was added MeLi (1.6 M in hexane, 398 μL,0.636 mmol) at −78° C. The mixture was allowed to warm to RT thenstirred for 2 h, after which time it had become a yellow suspension. Thevolatiles were removed under reduced pressure, and the yellow solidextracted with benzene (3×5 mL). The solvent was removed from theextracts under reduced pressure, the product washed with hexane (3×5mL), then dried in vacuo, leaving Example 2 as a yellow powder. Yield:0.125 g (64%). ¹H NMR (C₆D₆, 400.1 MHz): δ 7.28 (6H, overlapping 2×m, m-and p-C₆ H ₃ ^(i)Pr₂), 5.98 (2H, s, NCH), 3.91 (2H, sept., ³J=6.9 Hz, CH_(a)MeMe), 3.72 (2H, sept., ³J=6.9 Hz, CH _(b)MeMe), 2.69 (3H, s, NMe),2.57 (2H, m, NCH₂), 2.45 (1H, m, NCH₂), 2.28 (3H s, NMe), 2.16 (1H, m,NCH₂), 2.15 (3H, s, NMe), 2.03 (1H, m, NCH₂), 1.87 (1H, m, NCH₂), 1.72(1H, m, NCH₂), 1.59 (12H, app. t, app. ³J=7.9 Hz, overlapping CHMe_(a)Me and CHMe _(b)Me), 1.45 (5H, overlapping m, NCH₂), 1.35 (12H, app.d, app. ³J=6.2 Hz, overlapping CHMe _(a)Me and CHMe _(b)Me), −0.19(TiMe) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6 MHz): δ 147.4 (o-C ₆H₃ ^(i)Pr₂),142.3 (i-C ₆H₃ ^(i)Pr₂), 126.8 (p-C ₆H₃ ^(i)Pr₂), 123.2 (m-C₆H₃^(i)Pr₂), 116.8 (NCH), 56.8 (NCH₂), 56.4 (NCH₂), 55.5 (NCH₂), 55.4(NCH₂), 55.0 (NCH₂), 53.7 (NCH₂), 53.6 (NMe), 51.9 (NMe), 48.9 (NMe),37.6 (TiMe), 29.1 (C _(a)HMeMe), 28.8 (C _(b)HMeMe), 26.4 (CHMe ₂), 26.3(CHMe ₂), 23.8 (CHMe ₂), 23.3 (CHMe ₂) ppm. ¹¹B{¹H} NMR (C₆D₆, 128.4MHz): δ 14.0 ppm. Anal. found (calcd. for C₃₆H₆₀BClN₆Ti): C, 64.00(64.44); H, 8.88 (9.01); N, 12.39 (12.52)%.

Example 3

To a solution of Ti{NB(NAr′CH)₂}Cl₂(Me₃[9]aneN₃) (Example 1, 0.50 g,0.723 mmol) in toluene (20 mL) was added MeLi (1.6 M in hexane, 0.995mL, 1.59 mmol) at −78° C. The mixture was allowed to warm to RT thenheated to 60° C. and stirred for 20 h, after which time it had become ayellow suspension. The volatiles were removed under reduced pressure,and the yellow solid extracted with benzene (2×10 mL). The solvent wasremoved from the extracts under reduced pressure, then dried in vacuo,leaving Example 3 as a yellow powder. Yield: 0.325 g (69%). ¹H NMR(C₆D₆, 400.1 MHz): δ 7.29 (6H, overlapping 2×m, m- and p-C₆ H ₃^(i)Pr₂), 6.05 (2H, s, NCH), 3.97 (4H, sept., ³J=6.9 Hz, CHMeMe), 2.42(2H, m, NCH₂), 2.26 (6H, s, NMe cis to NB(NAr′CH)₂), 2.23 (3H, s, NMetrans to NB(NAr′CH)₂), 2.14 (2H, m, NCH₂), 1.97 (2H, m, NCH₂), 1.56(18H, overlapping d and m, CHMeMe and NCH₂), 1.40 (12H, d, ³J=6.9 Hz,CHMeMe), −0.03 (6H, s, TiMe) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6 MHz): δ 147.1(o-C ₆H₃ ^(i)Pr₂), 142.8 (i-C ₆H₃ ^(i)Pr₂), 126.0 (p-C ₆H₃ ^(i)Pr₂),122.8 (m-C₆H₃ ^(i)Pr₂), 116.4 (NCH), 55.3 (NCH₂), 54.7 (NCH₂), 51.4 (NMecis to NB(NAr′CH)₂), 48.4 (NMe trans to NB(NAr′CH)₂), 32.4 (TiMe), 28.5(CHMeMe), 25.8 (CHMeMe), 23.1 (CHMeMe) ppm. ¹¹B{¹H} NMR (C₆D₆, 128.4MHz): δ 14.0 ppm.

Example 4

To a solution of Ti{NB(NAr′CH)₂}Cl₂(NHMe₂)₂ (Precursor 7, 0.25 g, 0.410mmol) in toluene (10 mL) at −78° C. was added Me₃[6]aneN₃ (57.5 μL,0.409 mmol). The solution was then allowed to warm to RT, and stirredfor 3 h, after which time it had become an orange slurry. The slurry wasconcentrated (by ˜75%) and filtered, then the resulting solid washedwith hexane (3×2 mL) and dried in vacuo, yielding Example 4 as a paleorange powder. Yield: 0.154 g (58%). ¹H NMR (C₆D₆, 400.1 MHz): δ 7.27(6H, overlapping 2×m, m- and p-C₆ H ₃ ^(i)Pr₂), 5.83 (2H, s, NCH), 4.00(1H, d, ²J=7.3 Hz, NCH₂), 3.56 (4H, sept., ³J=6.9 Hz, CHMeMe), 3.33 (2H,d, ²J=7.9 Hz, NCH₂), 2.24 (1H, d, ²J=7.3 Hz, NCH₂), 1.95 (2H, d, ²J=7.9Hz, NCH₂), 1.87 (6H, s, NMe cis to NB(NAr′CH)₂), 1.66 (12H, d, ³J=6.9Hz, CHMeMe), 1.48 (3H, s, NMe trans to NB(NAr′CH)₂), 1.31 (12H, d,³J=6.9 Hz, CHMeMe) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6 MHz): δ 147.3 (o-C ₆H₃^(i)Pr₂), 141.0 (i-C ₆H₃ ^(i)Pr₂), 127.4 (p-C ₆H₃ ^(i)Pr₂), 123.7 (m-C₆H₃ ^(i)Pr₂), 116.5 (NCH), 77.0 (NCH₂), 76.0 (NCH₂), 40.6 (NMe cis toNB(NAr′CH)₂), 36.8 (NMe trans to NB(NAr′CH)₂), 29.3 (CHMeMe), 25.5(CHMeMe), 24.6 (CHMeMe) ppm. ¹¹B{¹H}NMR (C₆D₆, 128.4 MHz): δ 13.4 ppm.IR (NaCl plates, Nujol mull, cm⁻¹): 1595 (m), 1459 (s), 1380 (s), 1273(m), 1260 (m), 1175 (w), 1113 (w), 1083 (m), 935 (w), 899 (w), 799 (m),758 (w), 721 (w), 657 (w). Anal. found (calcd. for C₃₂H₅₁BCl₂N₆Ti): C,56.28 (59.19); H, 7.46 (7.92); N, 12.75 (12.94)%. Repeated attempts toobtain an elemental analysis with satisfactory % C values failed,presumably due to incomplete combustion of the compound.

Example 5

To a mixture of Ti{NB(N^(i)Pr)₂C₆H₄}Cl₂(NHMe₂)₂ (Precursor 8, 0.50 g,1.18 mmol) and HC(Me₂pz)₃ (0.352 g, 1.18 mmol) in a Schlenk tube wasadded toluene (15 mL). The mixture was heated to 75° C. and stirred for16 h. After this time, the volatiles were removed under reducedpressure, then the yellow solid washed with benzene (4×5 mL) and driedin vacuo, to yield Example 5 as a yellow powder. Yield: 0.478 g (64%).Diffraction-quality crystals were grown from a CH₂Cl₂ solution layeredwith hexane. ¹H NMR (CD₂Cl₂, 400.1 MHz, 183 K): δ 7.77 (1H, s,HC(Me₂pz)₃), 6.77 (2H, overlapping 2×m, 3,4-C₆H₄), 6.70 (1H, m, 2- or5-C₆H₄), 6.61 (1H, m, 2- or 5-C₆H₄), 6.14 (2H, s, 4-N₂C₃Me₂ H cis toNB(N^(i)Pr)₂C₆H₄), 5.89 (1H, s, 4-N₂C₃Me₂ H trans to NB(N^(i)Pr)₂C₆H₄),4.01 (1H, br. m, CH _(a)Me₂), 3.28 (1H, br. m, CH _(b)Me₂), 2.68 (6H, s,N₂C₃ Me ₂H cis to NB(N^(i)Pr)₂C₆H₄), 2.57 (6H, s, N₂C₃ Me ₂H cis toNB(N^(i)Pr)₂C₆H₄), 2.45 (3H, s, N₂C₃ Me ₂H trans to NB(N^(i)Pr)₂C₆H₄),2.42 (3H, s, N₂C₃ Me ₂H trans to NB(N^(i)Pr)₂C₆H₄), 1.75 (6H, br. m,CHMe _(2a)), 0.92 (6H, br. d, ³J=6.5 Hz, CHMe _(2b)) ppm. ¹³C{¹H} NMR(CD₂Cl₂, 100.6 MHz, 183 K): δ 155.9 (3-pz cis to NB(N^(i)Pr)₂C₆H₄),154.7 (3-pz trans to NB(N^(i)Pr)₂C₆H₄), 139.7 (5-pz cis toNB(N^(i)Pr)₂C₆H₄), 138.8 (5-pz trans to NB(N^(i)Pr)₂C₆H₄), 138.2(1,6-C₆H₄), 118.0 (2,5-C₆H₄), 116.6 (2,5-C₆H₄), 111.8 (3,4-C₆H₄), 108.3(4-pz trans to NB(N^(i)Pr)₂C₆H₄), 108.2 (4-pz cis to NB(N^(i)Pr)₂C₆H₄),67.2 (HC(Me₂pz)₃), 44.4 (C _(a)HMe₂), 44.0 (C _(b)HMe₂), 23.9 (CHMe_(2a)), 20.7 (CHMe _(2b)), 16.5 (N₂C₃ Me ₂H cis to NB(N^(i)Pr)₂C₆H₄),14.6 (N₂C₃ Me ₂H trans to NB(N^(i)Pr)₂C₆H₄), 11.7 (N₂C₃ Me ₂H cis toNB(N^(i)Pr)₂C₆H₄), 11.2 (N₂C₃ Me ₂H trans to NB(N^(i)Pr)₂C₆H₄) ppm.¹¹B{¹H} NMR (CD₂Cl₂, 128.4 MHz): δ 14.2 ppm. IR (NaCl plates, Nujolmull, cm⁻¹): 1595 (m), 1566 (s), 1414 (s), 1390 (s), 1336 (s), 1226 (m),1179 (m), 1139 (m), 1111 (w), 1043 (s), 992 (m), 978 (m), 647 (w), 913(s), 899 (w), 863 (w), 767 (w), 734 (s), 704 (s), 687 (m), 669 (w), 663(w), 632 (w), 555 (w). Anal. found (calcd. for C₂₈H₄₀BCl₂N₉Ti): C, 52.99(53.19); H, 6.33 (6.38); N, 19.82 (19.94)%.

Example 6

To a mixture of Ti{NB(NMe)₂C₆H₄}Cl₂(NHMe₂)₂ (Precursor 9, 0.50 g, 1.36mmol) and HC(Me₂pz)₃ (0.405 g, 1.36 mmol) in a Schlenk tube was addedtoluene (15 mL). The mixture was heated to 70° C. and stirred for 16 h.After this time, the volatiles were removed under reduced pressure, thenthe yellow-brown solid washed with benzene (2×10 mL) and dried in vacuo,to yield Example 6 as a yellow powder. Yield: 0.450 g (57%).Diffraction-quality crystals were grown from a CH₂Cl₂ solution layeredwith benzene. ¹H NMR (CD₂Cl₂, 400.1 MHz): δ 7.84 (1H, s, HC(Me₂pz)₃),6.81 (2H, m, 3,4-C₆H₄), 6.68 (2H, m, 2,5-C₆H₄), 6.61 (1H, m, 2,5-C₆H₄),6.11 (2H, s, 4-N₂C₃Me₂ H cis to NB(N^(i)Pr)₂C₆H₄), 5.91 (1H, s,4-N₂C₃Me₂ H trans to NB(N^(i)Pr)₂C₆H₄), 3.11 (6H, s, B(NMe)₂), 2.73 (6H,s, N₂C₃Me₂H cis to NB(N^(i)Pr)₂C₆H₄), 2.58 (6H, s, N₂C₃Me₂H cis toNB(N^(i)Pr)₂C₆H₄), 2.56 (3H, s, N₂C₃Me₂H trans to NB(N^(i)Pr)₂C₆H₄),2.45 (3H, s, N₂C₃Me₂H trans to NB(N^(i)Pr)₂C₆H₄) ppm. ¹³C{¹H} NMR(CD₂Cl₂, 100.6 MHz): δ 156.7 (3-pz cis to NB(N^(i)Pr)₂C₆H₄), 151.6 (3-pztrans to NB(N^(i)Pr)₂C₆H₄), 140.0 (5-pz cis to NB(N^(i)Pr)₂C₆H₄), 137.5(overlapping 5-pz trans to NB(N^(i)Pr)₂C₆H₄ and 1,6-C₆H₄), 118.4(3,4-C₆H₄), 109.0 (4-pz trans to NB(N^(i)Pr)₂C₆H₄), 108.7 (4-pz cis toNB(N^(i)Pr)₂C₆H₄), 107.3 (2,5-C₆H₄), 68.1 (HC(Me₂pz)₃), 28.9 (B(NMe)₂),16.2 (N₂C₃ Me ₂H cis to NB(N^(i)Pr)₂C₆H₄), 14.9 (N₂C₃ Me ₂H trans toNB(N^(i)Pr)₂C₆H₄), 11.6 (N₂C₃ Me ₂H cis to NB(N^(i)Pr)₂C₆H₄), 11.2 (N₂C₃Me ₂H trans to NB(N^(i)Pr)₂C₆H₄) ppm. ¹¹B{¹H} NMR (CD₂Cl₂, 128.4 MHz): δ14.0 ppm.

Example 7

To a suspension of Ti{NB(N^(i)Pr)₂C₆H₄}Cl₂(NHMe₂)₂ (Precursor 8, 0.50 g,1.18 mmol) in benzene (15 mL) was added Me₃[9]aneN₃ (228 μL, 1.18 mmol)via microsyringe. The mixture was stirred for 90 minutes at RT, thenfiltered. The orange solid was washed with benzene (10 mL), then driedin vacuo, to yield Example 7 as an orange powder. Yield: 0.401 g (67%).Diffraction-quality crystals were grown from a CH₂Cl₂ solution layeredwith hexane. ¹H NMR (CD₂Cl₂, 400.1 MHz): δ 6.99 (2H, m, 3,4-C₆H₄), 6.71(2H, m, 2,5-C₆H₄), 4.98 (2H, sept., ³J=7.0 Hz, CHMe₂), 3.69 (2H, m,NCH₂), 3.33 (6H, s, NMe cis to NB(N^(i)Pr)₂C₆H₄), 3.23 (2H, m, NCH₂),3.07 (2H, m, NCH₂), 2.99 (2H, m, NCH₂), 2.77 (2H, m, NCH₂), 2.56 (5H,overlapping s and m, NMe trans to NB(N^(i)Pr)₂C₆H₄, and NCH₂), 1.49(12H, d, ³J=7.0 Hz, CHMe ₂) ppm. ¹³C{¹H} NMR (CD₂Cl₂, 100.6 MHz): δ135.2 (1,6-C₆H₄), 117.3 (2,5-C₆H₄), 111.4 (3,4-C₆H₄), 57.9 (NCH₂), 57.8(NCH₂), 54.9 (NCH₂ and NMe cis to NB(N^(i)Pr)₂C₆H₄), 49.1 (NMe trans toNB(N^(i)Pr)₂C₆H₄), 45.5 (CHMe₂), 21.9 (CHMe ₂) ppm. ¹¹B{¹H} NMR (CD₂Cl₂,128.4 MHz): δ 14.5 ppm. IR (NaCl plates, Nujol mull, cm⁻¹): 1594 (m),1573 (w), 1483 (s), 1421 (s), 1288 (s), 1198 (m), 1140 (s), 1067 (s),1031 (w), 1000 (s), 984 (m), 892 (m), 864 (w), 784 (s), 738 (s), 682(w), 663 (m), 583 (w). EI-MS: m/z=504 [M]+(1%). Anal. found (calcd. forC₂₁H₃₉BCl₂N₆Ti): C, 49.85 (49.93); H, 7.89 (7.78); N, 16.48 (16.64)%.

Example 8

To a suspension of Ti{NB(N^(i)Pr)₂C₆H₄}Cl₂(NHMe₂)₂ (Precursor 8, 0.50 g,1.18 mmol) in benzene (15 mL) was added Me₃[6]aneN₃ (166 μL, 1.18 mmol)via microsyringe. The mixture was stirred for 90 minutes at RT, thenfiltered. The orange solid was washed with benzene (5 mL), then dried invacuo, to yield Example 8 as an orange powder. Yield: 0.330 g (60%).Diffraction-quality crystals were grown from a benzene solution at RT.¹H NMR (CD₂Cl₂, 500.3 MHz, 253 K): δ 6.91 (2H, m, 3,4-C₆H₄), 6.72 (2H,m, 2,5-C₆H₄), 4.84 (1H, d, ²J=7.9 Hz, NCH₂), 4.66 (2H, sept., ³J=6.8 Hz,CHMe₂), 4.21 (2H, d, ²J=7.8 Hz, NCH₂), 3.81 (1H, d, ²J=7.9 Hz, NCH₂),3.42 (2H, d, ²J=7.8 Hz, NCH₂), 2.86 (6H, s, NMe cis toNB(N^(i)Pr)₂C₆H₄), 2.20 (3H, s, NMe trans to NB(N^(i)Pr)₂C₆H₄), 1.50(12H, d, ³J=6.8 Hz, CHMe ₂) ppm. ¹³C{¹H} NMR (CD₂Cl₂, 125.7 MHz, 253 K):δ 134.6 (1,6-C₆H₄), 117.4 (2,5-C₆H₄), 110.1 (3,4-C₆H₄), 77.8 (NCH₂),77.3 (NCH₂), 44.8 (CHMe₂), 41.8 (NMe cis to NB(N^(i)Pr)₂C₆H₄), 37.3 (NMetrans to NB(N^(i)Pr)₂C₆H₄), 22.2 (CHMe ₂) ppm. ¹¹B{¹H} NMR (CD₂Cl₂,160.4 MHz, 253 K): δ 14.8 ppm. IR (NaCl plates, Nujol mull, cm¹): 1913(w), 1859 (w), 1805 (w), 1737 (w), 1597 (s), 1578 (m), 1409 (s), 1336(s), 1292 (s), 1224 (m), 1138 (s), 1128 (s), 1110 (s), 1033 (w), 1010(m), 996 (m), 939 (w), 903 (w), 866 (w), 766 (m), 743 (s), 678 (w), 667(w), 658 (m), 621 (w), 556 (m). Anal. found (calcd. for Cl₃H₃₃BCl₂N₆Ti):C, 46.87 (46.69); H, 7.34 (7.18); N, 18.05 (18.15)%.

Example 9

To a suspension of Ti{NB(NMe)₂C₆H₄}Cl₂(NHMe₂)₂ (Precursor 9, 0.50 g,1.36 mmol) in benzene (15 mL) was added Me₃[9]aneN₃ (263 μL, 1.36 mmol)via microsyringe. The mixture was stirred for 60 minutes at RT, thenfiltered. The orange solid was washed with benzene (5 mL), then dried invacuo, to yield Example 9 as an orange powder. Yield: 0.509 g (83%).Diffraction-quality crystals were grown from a CH₂Cl₂ solution layeredwith benzene. ¹H NMR (CD₂Cl₂, 400.1 MHz): δ 6.83 (2H, m, 3,4-C₆H₄), 6.72(2H, m, 2,5-C₆H₄), 3.70 (2H, m, NCH₂), 3.38 (6H, s, B(NMe)₂), 3.35 (6H,s, Me ₃[9]aneN₃ cis to NB(NMe)₂C₆H₄), 3.22 (2H, m, NCH₂), 3.01 (4H,overlapping 2×m, NCH₂), 2.78 (2H, m, NCH₂), 2.55 (5H, overlapping s andm, Me ₃[9]aneN₃ trans to NB(NMe)₂C₆H₄, and NCH₂) ppm. ¹³C{¹H} NMR(CD₂Cl₂, 100.6 MHz): δ 137.6 (1,6-C₆H₄), 118.5 (3,4-C₆H₄), 107.3(2,5-C₆H₄), 57.9 (NCH₂), 57.7 (NCH₂), 55.0 (NCH₂), 54.9 (Me ₃[9]aneN₃cis to NB(NMe)₂C₆H₄), 49.2 (Me ₃[9]aneN₃ trans to NB(NMe)₂C₆H₄), 29.9(B(NMe)₂) ppm. ¹¹B{¹H} NMR (CD₂Cl₂, 128.4 MHz): δ 14.9 ppm. IR (NaClplates, Nujol mull, cm⁻¹): 1809 (w), 1699 (w), 1602 (m), 1407 (s), 1312(s), 1225 (m), 1202 (w), 1127 (s), 1073 (s), 1004 (s), 893 (m), 779 (s),757 (s), 736 (m), 690 (m), 674 (m), 649 (m). Anal. found (calcd. forCl₄H₂₅BCl₂N₆Ti): C, 45.58 (45.47); H, 7.01 (6.96); N, 18.57 (18.72)%.

Example 10

To a suspension of Ti{NB(NMe)₂C₆H₄}Cl₂(NHMe₂)₂ (Precursor 9, 0.500 g,1.36 mmol) in benzene (15 mL) was added Me₃[6]aneN₃ (191 μL, 1.36 mmol)via microsyringe. The mixture was stirred for 60 minutes at RT, thenfiltered. The orange solid was washed with benzene (5 mL), then dried invacuo, to yield Example 10 as an orange powder. Yield: 0.410 g (74%).Diffraction-quality crystals were grown from a CH₂Cl₂ solution layeredwith hexane. ¹H NMR (CD₂Cl₂, 500.3 MHz, 253 K): δ 6.83 (2H, m,3,4-C₆H₄), 6.70 (2H, m, 2,5-C₆H₄), 4.80 (1H, d, ²J=7.9 Hz, NCH₂), 4.20(2H, d, ²J=7.9 Hz, NCH₂), 3.83 (1H, d, ²J=7.9 Hz, NCH₂), 3.48 (2H, d,²J=7.9 Hz, NCH₂), 3.29 (6H, s, B(NMe)₂), 2.85 (6H, s, NMe cis toNB(NMe)₂C₆H₄), 2.19 (3H, s, NMe trans to NB(NMe)₂C₆H₄) ppm. ¹³C{¹H} NMR(CD₂Cl₂, 125.7 MHz, 253 K): δ 136.7 (1,6-C₆H₄), 118.4 (3,4-C₆H₄), 107.3(2,5-C₆H₄), 77.8 (NCH₂), 77.3 (NCH₂), 41.9 (NMe cis to NB(NMe)₂C₆H₄),37.4 (NMe trans to NB(NMe)₂C₆H₄), 29.0 (B(NMe)₂) ppm. ¹¹B{¹H} NMR(CD₂Cl₂, 160.4 MHz, 253 K): δ 14.2 ppm. IR (NaCl plates, Nujol mull,cm⁻¹): 2460 (w), 1602 (m), 1430 (s), 1413 (s), 1395 (s), 1273 (s), 1230(w), 1175 (m), 1119 (s), 1006 (m), 935 (m), 892 (w), 783 (m), 734 (s),691 (w), 662 (w), 642 (s), 623 (w), 610 (w). Anal. found (calcd. forC₁₄H₂₅BCl₂N₆Ti): C, 39.07 (41.32); H, 5.94 (6.19); N, 16.27 (20.65)%.

Example 11

To a solution of Ti{NB(NAr′CH)₂}Cl₂(NHMe₂)₂ (Precursor 7, 0.35 g, 0.573mmol) in toluene (15 mL) was added Me₄DACH (168 μL, 0.860 mmol) viamicrosyringe at RT. The mixture was heated to 60° C. and then stirredfor 16 h, after which time it had become an orange solution. Thevolatiles were removed under reduced pressure, and the orange solidwashed with hexane (3×8 mL), then dried in vacuo, leaving Example 11 asa pale orange powder. Yield: 0.344 g (85%). The ¹H NMR spectrumindicated an approximately 55:45 mixture of the cis and trans isomers.Diffraction-quality crystals were grown from a hexane solution at 4° C.

Major isomer (cis): ¹H NMR (Toluene-d₈, 400.1 MHz): δ 7.28 (6H,overlapping 2×m, m- and p-C₆ H ₃ ^(i)Pr₂), 5.85 (2H, s, NCH), 3.70 (4H,sept., ³J=6.9 Hz, CHMeMe), 3.20 (1H, m, H_(f(down))), 3.02 (1H, m,H_(e(down))), 2.84 (1H, d, ²J=14.6 Hz, H_(g(down))), 2.54 (3H, s,NMe_(b)), 2.36 (3H, s, NMe_(d)), 2.14 (1H, overlapping d, ²J=14.6 Hz,H_(h(down))), 2.13 (3H, s, NMe_(c)), 2.00 (3H, s, NMe_(a)), 1.66 (12H,app.dd, ³J=6.8 Hz, CHMeMe), 1.61 (1H, m, H_(f(up))), 1.51 (1H, d,²J=14.6 Hz, H_(g(up))), 1.48 (1H, m, H_(e(up))), 1.31 (12H, overlappingapp.dd, ³J=6.8 Hz, CHMeMe), 1.25 (1H, overlapping d, ²J=14.6 Hz,H_(h(up))), 0.05 (3H, s, CMe) ppm. ¹³C{¹H} NMR (Toluene-d₈, 100.6 MHz):δ 148.0 (o-C ₆H₃ ^(i)Pr₂), 142.3 (i-C ₆H₃ ^(i)Pr₂), 128.0 (p-C ₆H₃^(i)Pr₂), 124.3 (m-C ₆H₃ ^(i)Pr₂), 117.8 (NCH), 71.0 (C_(g)), 68.7(C_(h)), 64.1 (C_(f)), 61.1 (CMe), 59.9 (C_(e)), 54.9 (NMe_(d)), 50.9(NMe_(a)), 48.2 (NMe_(b)), 46.9 (NMe_(c)), 29.8 (CHMe₂), 24.1-27.8 (CHMe₂), 11.6 (CMe) ppm. ¹¹B{¹H} NMR (Toluene-d₈, 128.4 MHz): δ 14.0 ppm.

Minor isomer (trans): ¹H NMR (Toluene-d₈, 400.1 MHz): δ 7.28 (6H,overlapping 2×m, m- and p-C₆ H ₃ ^(i)Pr₂), 5.87 (2H, s, NCH), 3.69 (4H,sept., ³J=6.9 Hz, CHMeMe), 3.33 (2H, m, H_(a(down))), 2.41 (2H, d,²J=14.4 Hz, H_(b(down))), 2.29 (6H, s, NMe), 1.84 (2H, m, H_(a(up))),1.80 (6H, s, NMe₂), 1.59 (12H, d, ³J=6.8 Hz, CHMeMe), 1.48 (2H, d,²J=14.4 Hz, H_(b(up))), 1.30 (12H, d, ³J=6.8 Hz, CHMeMe),0.00 (3H, s,CMe) ppm. ¹³C{¹H}NMR (Toluene-d₈, 100.6 MHz): δ 147.9 (o-C₆H₃ ^(i)Pr₂),142.2 (i-C₆H₃ ^(i)Pr₂), 127.9 (p-C ₆H₃ ^(i)Pr₂), 124.2 (m-C ₆H₃^(i)Pr₂), 117.9 (NCH), 70.3 (C_(b)), 64.1 (C_(a)), 59.8 (CMe), 54.6(NMe), 43.2 (NMe₂), 29.8 (CHMeMe), 27.3 (CHMeMe), 24.4 (CHMeMe), 11.1(CMe) ppm. ¹¹B{¹H} NMR (Toluene-d₈, 128.4 MHz): δ 14.0 ppm.

Common data: IR (NaCl plates, Nujol mull, cm⁻¹): 2356 (w), 1580 (w),1406 (m), 1317 (m), 1249 (m), 1223 (w), 1173 (w), 1111 (m), 1072 (m),1013 (m), 965 (m), 920 (m), 830 (m), 808 (m), 754 (s), 710 (m), 652 (s).Anal. found (calcd. for C₃₆H₅₉BCl₂N₆Ti): C, 61.38 (61.29); H, 8.58(8.43); N, 11.95 (11.91)%.

Example 12

To a solution of Ti{NB(N^(i)Pr)₂C₆H₄}Cl₂(NHMe₂)₂ (Precursor 8, 0.35 g,0.826 mmol) in toluene (15 mL) was added Me₄DACH (212 μL, 1.07 mmol) viamicrosyringe at RT. The mixture was heated to 50° C. and then stirredfor 16 h, after which time it had become a brown solution. The volatileswere removed under reduced pressure, and the orange solid washed withhexane (3×10 mL), then dried in vacuo, leaving Example 12 as an orangepowder. Yield: 0.369 g (86%). The ¹H NMR spectrum indicated anapproximately 2:1 mixture of the cis and trans isomers.Diffraction-quality crystals were grown from a benzene solution at RT.

Major isomer (cis): ¹H NMR (CD₂Cl₂, 400.1 MHz): δ 6.96 (2H, m,3,4-C₆H₄), 6.72 (2H, m, 2,5-C₆H₄), 4.95 (4H, sept., ³J=6.9 Hz, CHMe₂),3.83 (1H, m, H_(f(down))), 3.43 (1H, m, H_(e(down))), 3.40 (1H,overlapping d, ²J=14.6 Hz, H_(g(down))), 3.29 (3H, s, NMe_(b)), 3.19(3H, s, NMe_(d)), 3.10 (1H, overlapping d, ²J=14.6 Hz, H_(h(down))),2.77 (3H, s, NMe_(c)), 2.69 (1H, m, H_(e(up))), 2.60 (1H, overlapping d,²J=14.6 Hz, H_(g(up))), 2.46 (1H, overlapping m, H_(f(up))), 2.44 (3H,s, NMe_(a)), 2.36 (1H, overlapping d, ²J=14.6 Hz, H_(h(up))), 1.51 (12H,overlapping d, ³J=6.9 Hz, CHMe ₂), 0.95 (3H, s, CMe) ppm. ¹³C{¹H} NMR(CD₂Cl₂, 100.6 MHz): δ 135.0 (1,6-C₆H₄), 117.2 (2,5-C₆H₄), 111.1(3,4-C₆H₄), 71.1 (C_(g)), 69.1 (C_(h)), 63.8 (C_(f)), 62.8 (CMe), 59.6(C_(e)), 55.0 (NMe_(b)), 50.6 (NMe_(a)), 48.0 (NMe_(d)), 46.3 (NMe_(c)),45.2 (CHMe₂), 21.9 (CHMe ₂), 11.7 (CMe) ppm. ¹¹B{¹H} NMR (CD₂Cl₂, 128.4MHz): δ 13.6 ppm.

Minor isomer (trans): ¹H NMR (CD₂Cl₂, 400.1 MHz): δ 6.96 (2H, m,3,4-C₆H₄), 6.72 (2H, m, 2,5-C₆H₄), 4.95 (4H, sept., ³J=6.9 Hz, CHMe₂),4.96 (4H, sept., ³J=6.9 Hz, CHMeMe), 4.00 (2H, d, ³J=6.4 Hz,H_(a(down))), 3.81 (2H, d, ²J=14.4 Hz, H_(b(down))), 3.01 (2H, d, ³J=6.4Hz, H_(a(up))), 2.72 (2H, d, ²J=14.4 Hz, H_(b(up))), 3.08 (6H, s, NMe),2.30 (6H, s, NMe₂), 1.51 (12H, overlapping d, ³J=6.9 Hz, CHMe ₂), 0.83(3H, s, CMe) ppm. ¹³C{¹H} NMR (CD₂Cl₂, 100.6 MHz): δ 134.9 (1,6-C₆H₄),117.3 (2,5-C₆H₄), 111.2 (3,4-C₆H₄), 70.6 (C_(b)), 63.8 (C_(a)), 59.8(CMe), 54.2 (NMe), 45.2 (CHMe₂), 42.9 (NMe₂), 21.9 (CHMe ₂), 11.0 (CMe).¹¹B{¹H} NMR (CD₂Cl₂, 128.4 MHz): δ 13.6 ppm.

Common data: IR (NaCl plates, Nujol mull, cm⁻¹): 2361 (w), 1940 (w),1591 (s), 1410 (w), 1333 (m), 1285 (s), 1223 (w), 1201 (m), 1142 (s),1086 (s), 1055 (w), 1024 (s), 987 (m), 931 (s), 881 (w), 827 (m), 785(s), 754 (s), 664 (s). Anal. found (calcd. for C₃₆H₅₉BCl₂N₆Ti): C, 51.02(50.90); H, 8.02 (7.96); N, 16.00 (16.19)%.

Example 13

To a Schlenk tube of Ti{NB(NAr′CH)₂}Cl₂(NHMe₂)₂ (Precursor 7, 0.27 g,0.443 mmol) and DD₃[6]aneN₃ (0.262 g, 0.443 mmol) was added toluene (10mL) at RT and it was stirred for 6 h. Then, the volatiles were removedunder reduced pressure and the residue was redissolved in toluene. Thiswas repeated 4 times for every 6 h stirring, after which time it hadbecome a red solution. It was then dried in vacuo, leaving Example 13 asan orange wax. Yield: 0.468 g (95%). The ¹H NMR spectrum indicated 7% 1and 7% unreacted 7 contained in the desired product. ¹H NMR (C₆D₆, 400.1MHz): δ 7.31 (6H, overlapping 2×m, m- and p-C₆ H ₃ ^(i)Pr₂), 5.82 (2H,s, NCH), 4.35 (1H, d, ²J=6.9 Hz, NCH₂N), 3.76 (2H, d, ²J=6.9 Hz, NCH₂N),3.63 (4H, sept., ³J=6.9 Hz, CHMeMe), 3.11 (2H, m, CH₂), 2.62 (2H, d,²J=6.9 Hz, NCH₂N), 2.59 (2H, m, CH₂), 2.51 (2H, m, CH₂), 2.06 (2H, m,CH₂), 1.95 (2H, d, ²J=7.9 Hz, NCH₂), 1.73 (12H, d, ³J=6.9 Hz, CHMeMe),1.48-0.95 (25H, overlapping m, CH₂), 1.34 (12H, d, ³J=6.9 Hz, CHMeMe),0.92 (9H, overlapping t, CH₂Me) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6 MHz): δ146.9 (o-C ₆H₃ ^(i)Pr₂), 140.9 (i-C ₆H₃ ^(i)Pr₂), 127.2 (p-C ₆H₃^(i)Pr₂), 123.8 (m-C ₆H₃ ^(i)Pr₂), 116.4 (NCH), 73.7 (NCH₂N), 73.0(NCH₂N), 56.2 (CH₂), 53.1 (CH₂), 51.8 (CH₂), 30.2-27.6 (CH₂), 29.8(CHMeMe), 25.2 (CHMeMe), 24.4 (CHMeMe), 22.8 (CH₂), 14.1 (CH₃) ppm.¹¹B{¹H} NMR (C₆D₆, 128.4 MHz): δ 13.9 ppm. IR (NaCl plates, Nujol mull,cm⁻¹): 1580 (m), 1322 (w), 1277 (w), 1257 (m), 1111 (m), 1094 (w), 1069(w), 1015 (m), 942 (m), 897 (m), 801 (s), 763 (s), 715 (s), 650 (s).Anal. found (calcd. for C₆₅H₁₁₇BCl₂N₆Ti): C, 70.08 (70.19); H, 10.46(10.60); N, 7.54 (7.56)%.

Example 14

To a solution of Ti{NB(NAr′CH)₂}Cl₂(NHMe₂)₂ (Precursor 7, 0.30 g, 0.492mmol) in toluene (10 mL) at RT was added Hex₃[6]aneN₃ (193 μL, 0.492mmol) and stirred for 3 h. Then, the volatiles were removed underreduced pressure and the residue was redissolved in toluene. This wasrepeated for every 3 h stirring, after which time it had become a yellowsolution. The volatiles were removed under reduced pressure, and theyellow solid washed with hexane (3×5 mL), then dried in vacuo, leavingExample 14 as a yellow powder. Yield: 0.262 g (62%). ¹H NMR (C₆D₆, 400.1MHz): δ 7.29 (6H, overlapping 2×m, m- and p-C₆H₃Pr₂), 5.82 (2H, s, NCH),4.31 (1H, d, ²J=7.2 Hz, NCH₂N), 3.72 (2H, d, ²J=7.2 Hz, NCH₂N), 3.64(4H, sept., ³J=6.9 Hz, CHMeMe), 3.14 (1H, d, ²J=7.2 Hz, NCH₂N), 3.07(2H, m, CH₂), 2.57 (2H, d, ²J=7.2 Hz, NCH₂N), 2.50 (2H, m, CH₂), 2.03(2H, m, CH₂), 1.71 (12H, d, ³J=6.9 Hz, CHMeMe), 1.37-1.03 (9H,overlapping m, CH₂), 1.33 (12H, d, ³J=6.9 Hz, CHMeMe), 1.01 (6H, t,³J=7.3 Hz, CH₂ Me), 0.84 (3H, t, ³J=7.3 Hz, CH₂ Me) ppm. ¹³C{¹H} NMR(C₆D₆, 100.6 MHz): δ 146.9 (o-C ₆H₃ ^(i)Pr₂), 140.8 (i-C ₆H₃ ^(i)Pr₂),127.2 (p-C ₆H₃ ^(i)Pr₂), 123.4 (m-C ₆H₃ ^(i)Pr₂), 116.4 (NCH), 73.6(NCH₂N), 73.0 (NCH₂N), 56.2 (NCH₂), 51.7 (NCH₂), 32.2 (CH₂), 31.9 (CH₂),29.0 (CHMeMe), 27.3 (CH₂), 25.2 (CHMeMe), 25.0 (CH₂), 24.3 (CHMeMe),24.1 (CH₂), 23.1 (CH₂), 23.0 (CH₂), 14.3 (CH₂ Me), 14.2 (CH₂ Me) ppm.¹¹B{¹H} NMR (C₆D₆, 128.4 MHz): δ 14.5 ppm. IR (NaCl plates, Nujol mull,cm⁻¹): 2354 (w), 1584 (w), 1416 (w), 1331 (w), 1308 (w), 1261 (m), 1277(m), 1232 (w), 1160 (m), 1110 (s), 1084 (m), 1068 (w), 1011 (s), 945(s), 894 (s), 805 (s), 751 (s), 720 (m), 647 (s). Anal. found (calcd.for CO₇H₃₃BCl₂N₆Ti): C, 65.43 (65.50); H, 9.68 (9.71); N, 9.59 (9.75)%.

Example 15

To a solution of Ti{NB(NAr′CH)₂}Cl₂(py)₃ (Precursor 10, 0.35 g, 0.453mmol) in toluene (10 mL) at RT was added BF₃—OEt₂ (173 μL, 1.359 mmol),which immediately resulted a dark green solution. After stirring thesolution for 10 mins at RT, the solution was transferred via cannulainto another Schlenk tube charged with Bn₃[6]aneN₃ (0.17 g, 0.453 mmol)and stirred at RT for 1 h, after which time it had become a yellowsolution. Then the toluene solution was concentrated to 3 mL and layeredwith 15 mL hexane at RT, resulting in yellow crystals of Example 15after 4 days. Yield: 0.224 g (48%). The ¹H NMR spectrum indicated oneequivalent of by-product BF₃-py was co-crystallised. ¹H NMR (C₆D₆, 400.1MHz): δ 7.30 (4H, d, ³J=7.3 Hz, m-C₆ H ₃ ^(i)Pr₂), 7.19 (4H, m, o-C₆ H₃Pr₂), 6.96 (8H, overlapping m, o- and m-C₆H₅), 6.91 3 H, overlapping m,p-C₆H₅), 6.67 (4H, overlapping m, o- and m-C₆H₅), 5.89 (2H, s, NCH),4.93 (1H, d, ²J=7.2 Hz, NCH₂N), 4.36 (2H, d, ²J=14.7 Hz, CH ₂Ph), 3.89(2H, d, ²J=7.2 Hz, NCH₂N), 3.78 (4H, sept., ³J=6.9 Hz, CHMeMe), 3.76(2H, d, ²J=14.7 Hz, CH ₂Ph), 3.10 (1H, d, ²J=7.2 Hz, NCH₂N), 3.01 (2H,s, CH ₂Ph), 2.13 (2H, d, ²J=7.2 Hz, NCH₂N), 1.80 (12H, d, ³J=6.9 Hz,CHMeMe), 1.35 (12H, d, ³J=6.9 Hz, CHMeMe) ppm. ¹³C{¹H} NMR (C₆D₆, 100.6MHz): δ 147.0 (o-C ₆H₃ ^(i)Pr₂), 140.8 (i-C ₆H₃ ^(i)Pr₂), 132.2(i-C₆H₅), 130.5-128.3 (o-, m- and p-C₆H₅), 127.4 (p-C ₆H₃ ^(i)Pr₂),123.5 (m-C ₆H₃ ^(i)Pr₂), 116.4 (NCH), 73.1 (NCH₂N), 73.0 (NCH₂N), 60.5(CH₂Ph), 55.8 (CH₂Ph), 29.0 (CHMeMe), 25.1 (CHMeMe), 24.6 (CHMeMe) ppm.¹¹B{¹H} NMR (C₆D₆, 128.4 MHz): δ 15.1 ppm. IR (NaCl plates, Nujol mull,cm⁻¹): 2367 (w), 1628 (s), 1496 (w), 1344 (w), 1304 (w), 1280 (w), 1222(w), 1117 (m), 1114 (s), 1088 (m), 1069 (m), 1015 (s), 968 (s), 934 (m),895 (s), 805 (s), 779 (s), 763 (s), 698 (s), 687 (s), 656 (s), 616 (m).Residual BF₃-py could not be fully separated and a satisfactoryelemental analysis was not obtained.

COMPARATIVE EXAMPLES

Comparative Example 1 was prepared according to Adams et al.,Organometallics, 2006, 25 (16), 3888-3903. Comparative Example 2 wasprepared according to Bigmore et al., Chem. Commun., 2006, 436-438.

Example 16—Catalyst Immobilisation

The borylimide catalysts (Examples 1-15) and comparative example 1-2were immobilised on polymethylaluminoxane (sMAO) using previouslyreported methodology (T. A. Q. Arnold, Z. R. Turner, J. C. Buffet and D.O'Hare, J. Organomet. Chem., 2016, 822, 85-90; D. A. X. Fraser, Z. R.Turner, J. C. Buffet and D. O'Hare, Organometallics, 2016, 35,2664-2674).

In a glovebox, sMAO (250 mg, 200 eqv.) and the desired catalyst (1 eqv.)were added to a Schlenk flask. Toluene (40 mL) was then added and theslurry was heated at 60° C. for one hour with occasional agitation byhand. After this time, the mixture was filtered, leaving thesMAO-immobilised catalyst (1:200 ratio of Ti:Al) as a pale yellow powderwhich was then dried in vacuo.

Example 17—Polymerisation Studies Ethylene Polymerisation: Slurry-Phase

In a glovebox, the immobilized catalyst (10 mg) was weighed into athick-walled ampoule, along with triisobutylaluminum (TIBA, 150 mg) asco-catalyst, and hexane (50 mL). The ampoule was then cycled on to aSchlenk line and the N₂ atmosphere was partially removed under vacuum.The slurry was heated to the desired temperature (50, 60, 70 or 80 TC)and stirred vigorously prior to the addition of ethylene at 3 bardynamic pressure. The mass of polyethylene produced was monitored after15, 30 and 60 minutes. To terminate the polymerisation the ampoule wasremoved from the heat and ethylene was removed from the system undervacuum and replaced with N₂. The resulting polymer was filtered, washedseveral times with pentane, and dried.

The slurry-phase polymerisation results are summarised in Table 1 below.

TABLE 1 Activity/ Immobilised Temp./ Reaction kg_(PE) mol⁻¹ M_(w)/×10⁶M_(n)/×10⁶ Catalyst ° C. time h⁻¹ bar⁻¹ g mol⁻¹ g mol⁻¹ M_(w)/M_(n)sMAO- 50 15 min 2980 3.24 1.00 3.2 Example 1 60 30 min 3790 2.19 0.544.1 70 15 min 4170 1.57 0.25 6.4 sMAO- 50 15 min 1300 3.78 1.02 3.7Example 3 60 15 min 1400 3.57 0.90 4.0 70 15 min 1290 2.75 0.59 4.7sMAO- 50 15 min  980 1.95 0.57 3.4 Example 4 60 15 min  740 2.46 0.455.5 70 15 min  620 1.79 0.31 5.7 80 15 min  490 — — — 50 60 min  100^(a) — — — 60 60 min   80^(a) — — — 70 60 min   80^(a) — — — 80 60min   70^(a) — — — sMAO- 50 15 min  790 3.99 0.83 4.8 Example 5 60 15min  780 3.88 0.62 6.3 70 15 min  890 3.19 0.33 9.6 sMAO- 50 15 min  9803.94 0.75 5.3 Example 6 60 15 min 1140 3.50 0.67 5.2 70 15 min 1150 2.840.30 9.3 sMAO- 50 30 min  20 — — — Example 7 60 30 min  40 — — — 70 30min  80 — — — sMAO- 50 30 min  180 — — — Example 8 60 30 min  90 — — —70 30 min  70 — — — sMAO- 50 30 min  40 — — — Example 9 60 30 min  20 —— — 70 30 min  10 — — — sMAO- 50 30 min  230 — — — Example 10 60 30 min 50 — — — 70 30 min  40 — — — sMAO- 50 30 min  180 2.39 0.25 9.5 Example11 60 15 min  230 1.55 0.14 11.2 70 30 min  200 — — — sMAO- 50 30 min 10 — — — Example 12 60 30 min  30 — — — 70 30 min  20 — — — sMAO- 50 15min  410 — — — Example 13 60 15 min  480 0.47 0.07 6.5 70 15 min  5900.85 0.23 3.7 sMAO- 50 15 min  430 — — — Example 14 60 15 min  590 1.610.38 4.3 70 15 min  650 0.88 0.12 7.1 sMAO- 50 30 min  400 — — — Example15 60 30 min  290 — — — 70 30 min  840 — — — sMAO- 60 15 min 3230 1.090.04 26.9 Comparative Example 1 sMAO- 70 15 min 8140 1.00 0.09 10.6Comparative Example 2 ^(a)performed by using TEA, instead of TIBA, asscavenger.

Ethylene Polymerisation: Solution-Phase

In a glovebox, the catalyst (0.5 mg or 2 mg) was weighed into athick-walled ampoule, along with methylaluminoxane (MAO, 500 eqv for 2mg catalyst loading or 1000 eqv for 0.5 mg catalyst loading) asco-catalyst, and toluene (50 mL). The ampoule was then cycled on to aSchlenk line and the N₂ atmosphere was partially removed under vacuum.The slurry was stirred vigorously at room temperature prior to theaddition of ethylene at 3 bar dynamic pressure. The mass of polyethyleneproduced was monitored after 2, 6 and 15 minutes. To terminate thepolymerisation the ethylene was removed from the system under vacuum andreplaced with N₂. The resulting polymer was filtered washed severaltimes with pentane, and dried.

The solution-phase polymerisation results are summarised in Table 2below.

TABLE 2 Activity/ M_(w)/ Catalyst kg_(PE) mol⁻¹ h⁻¹ ×10⁶ g M_(n)/×10⁶M_(w)/ Catalyst loading bar⁻¹ (reaction time) mol⁻¹ g mol⁻¹ M_(n)Example 1 0.5 mg 12860 1.99 0.13 15.6 0.5 mg 6740 2.93 0.56 5.3 Example3   2 mg 4440^(a) — — — Example 4 0.5 mg 8270 3.42 0.72 4.8 Example 5  2 mg 2240 3.58 1.03 3.5 Example 6   2 mg 1090 3.48 0.98 3.5 Example 7  2 mg  150 (6 min) — — — Example 8   2 mg 140 — — — Example 9   2 mg  30 (15 min) — — — Example 10   2 mg 80 — — — Example 11   2 mg 29602.35 0.18 12.8 Example 12   2 mg trace — — — Example 13 0.5 mg 9630 3.090.70 4.4 Example 14 0.5 mg 7590 — — — Example 15   2 mg trace — — —Comparative   2 mg 1840 (2 min) — — — Example 1 Comparative   2 mg 2880(2 min) — — — Example 2 ^(a)performed with 1 eqv. [Ph₃C][B(Ar^(F))₄](Ar^(F) = C₆F₅, TBF₂₀) and 1000 eqv. TIBA.

The results presented in Tables 1 and 2 illustrate that the examplecatalysts are effective in the polymerisation of olefins, such asethylene, both in the slurry and solution phases, typically with goodcatalyst activities. They produced linear polyethylenes with ultra-highmolecular weight and/or moderate polydispersity.

While specific embodiments of the invention have been described hereinfor the purpose of reference and illustration, various modificationswill be apparent to a person skilled in the art without departing fromthe scope of the invention as defined by the appended claims.

1. A compound of Formula (I):

wherein: M is selected from titanium, zirconium and hafnium; X¹ and X²are independently selected from halo, hydrogen, a phosphonate, sulfonateor boronate group, amino, (1-6C)alkyl, (1-6C)alkoxy, aryl, aryloxy andheterocycloalkyl (such as THF), wherein said (1-6C)alkyl, (1-6C)alkoxy,aryl and aryloxy groups may be optionally substituted with one of moregroups selected from halo, oxo, hydroxy, amino, nitro, (1-6C)alkyl,(2-6C)alkenyl, (2-6C)alkynyl, (1-6C)haloalkyl, (1-6C)alkoxy, aryl andSi[(1-4C)alkyl]₃; Y is BR¹R²; Z is a polydentate ligand coordinated to Mby at least 2 donor atoms Q, wherein each Q is independently selectedfrom N, O, S and P; R¹ and R² are independently selected from NR³R⁴,OR⁵, SR⁶ and CR⁷R⁸R⁹; R³, R⁴, R⁵, R⁶, R⁷, R⁸ and R⁹ are independentlyselected from hydrogen, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, aryland heteroaryl, wherein said (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl,aryl and heteroaryl groups are optionally substituted with one or moresubstituents selected independently from halo, hydroxy, amino, nitro,(1-6C)alkyl and (1-6C)haloalkyl; or R¹ and R² are linked, such that whentaken in combination with the boron atom to which they are attached,they form a group:

wherein ring A is a carbocyclic or heterocyclic ring, optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)haloalkyl, aryland heteroaryl, wherein said aryl and heteroaryl groups are optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl.
 2. Thecompound according to claim 1, wherein R¹ and R² are both NR³R⁴.
 3. Thecompound according to claim 1, wherein R¹ and R² are linked, such thatwhen taken in combination with the boron atom to which they areattached, they form a group:

wherein X is a heteroatom chosen from NR¹⁰, O and S; the heterocyclicring A is optionally substituted with one or more substituents selectedindependently from halo, hydroxy, amino, (1-6C)alkyl, (1-6C)alkoxy,(1-6C)haloalkyl, aryl and heteroaryl, wherein said aryl and heteroarylgroups are optionally substituted with one or more substituents selectedindependently from halo, hydroxy, amino, nitro, (1-6C)alkyl and(1-6C)haloalkyl; and R¹⁰ is (1-6C)alkyl, aryl or heteroaryl, whereinsaid (1-6C)alkyl, aryl and heteroaryl groups are optionally substitutedwith one or more substituents selected independently from halo, hydroxy,amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl.
 4. The compound accordingto claim 1, wherein Y is selected from one of the following groups:

wherein each R¹⁰ is independently (1-6C)alkyl, aryl or heteroaryl,wherein said (1-6C)alkyl, aryl and heteroaryl groups are optionallysubstituted with one or more substituents selected independently fromhalo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl.
 5. Thecompound according to claim 3, wherein R¹⁰ is an aryl group optionallysubstituted with one or more substituents selected independently from(1-6C)alkyl and (1-6C)haloalkyl.
 6. The compound according to claim 3,wherein R¹⁰ is (1-6C)alkyl.
 7. The compound according to claim 1,wherein Z is a tri- or tetra-dentate ligand coordinated to M by 3-4donor atoms Q.
 8. The compound according to claim 1, wherein Z is theligand according to formula (II):

wherein Q¹, Q² and Q³ are NR¹²R¹³ or a heteroaryl group containing atleast one nitrogen atom, said heteroaryl group optionally substitutedwith one or more substituents selected from halo, hydroxy, amino, nitro,(1-6C)alkyl, (1-6C)alkoxy, —S-(1-6C)alkyl and (1-6C)haloalkyl; R¹² andR¹³ are independently absent, hydrogen, (1-20C)alkyl, aryl or heteroarylas valency permits, wherein said (1-20C)alkyl, aryl and heteroarylgroups are optionally substituted with one or more substituents selectedfrom halo, hydroxy, amino, nitro, (1-6C)alkyl, (1-6C)haloalkyl and aryl;L¹, L² and L³ are absent, a bond, (1-3C)alkylene or (2-3C)alkenylene,said (1-3C)alkylene or (2-3C)alkenylene moieties being optionallysubstituted with one or more substituents selected from (1-3C)alkyl,halo, hydroxy, (1-3C)alkoxy, aryl or heteroaryl; L⁴ is absent, CR¹⁴,[BR¹⁵]⁻, (1-3C)alkylene or (2-3C)alkylenylene, said (1-3C)alkylene or(2-3C)alkenylene moieties being optionally substituted with one or moresubstituents selected from (1-3C)alkyl, halo, hydroxy, (1-3C)alkoxy,aryl or heteroaryl; R¹⁴ is absent, hydrogen, (1-6C)alkyl, halo, hydroxy,(1-3C)alkoxy, aryl or heteroaryl; and R¹⁵ is hydrogen or (1-6C)alkyl. 9.The compound according to claim 8, wherein Z is a ligand of formula(IIA) or (IIB):

wherein L¹, L² and L³ are a bond, (1-3C)alkylene or (2-3C)alkenylene,said (1-3C)alkylene or (2-3C)alkenylene moieties being optionallysubstituted with one or more substituents selected from (1-3C)alkyl,halo, hydroxy, (1-3C)alkoxy, aryl or heteroaryl; and L⁴ is CR¹⁴,(1-3C)alkylene or (2-3C)alkylenylene, said (1-3C)alkylene or(2-3C)alkenylene moieties being optionally substituted with one or moresubstituents selected from (1-3C)alkyl, halo, hydroxy, (1-3C)alkoxy,aryl or heteroaryl.
 10. The compound according to claim 1, wherein Z isselected from one of the following ligands:

wherein R¹² is (1-20C)alkyl optionally substituted with one or moresubstituents selected from halo, hydroxy, amino, nitro, (1-6C)alkyl,(1-6C)haloalkyl and aryl.
 11. The compound according to claim 1, whereinM is titanium.
 12. The compound according to claim 1, wherein X¹ and X²are independently selected from halo, (1-6C)alkyl and (1-6C)alkoxy. 13.A composition comprising a compound according to claim 1 immobilised ona solid support material.
 14. The composition according to claim 13,wherein the solid support material is selected from silica, alumina,zeolite, layered double hydroxide, methylaluminoxane-activated silica,methylaluminoxane-activated layered double hydroxide and solidmethylaluminoxane.
 15. A process for the polymerisation of at least oneolefin, the process comprising contacting the at least one olefin with acompound of claim
 1. 16. The compound according to claim 4, wherein:each R¹⁰ is independently an aryl group optionally substituted with oneor more substituents selected independently from (1-6C)alkyl and(1-6C)haloalkyl; and Z is a tri- or tetra-dentate ligand coordinated toM by 3-4 donor atoms Q.
 17. The compound according to claim 16, whereinZ is the ligand according to formula (II):

wherein Q¹, Q² and Q³ are NR¹²R¹³ or a heteroaryl group containing atleast one nitrogen atom, said heteroaryl group optionally substitutedwith one or more substituents selected from halo, hydroxy, amino, nitro,(1-6C)alkyl, (1-6C)alkoxy, —S-(1-6C)alkyl and (1-6C)haloalkyl; R¹² andR¹³ are independently absent, hydrogen, (1-20C)alkyl, aryl or heteroarylas valency permits, wherein said (1-20C)alkyl, aryl and heteroarylgroups are optionally substituted with one or more substituents selectedfrom halo, hydroxy, amino, nitro, (1-6C)alkyl, (1-6C)haloalkyl and aryl;L¹, L² and L³ are absent, a bond, (1-3C)alkylene or (2-3C)alkenylene,said (1-3C)alkylene or (2-3C)alkenylene moieties being optionallysubstituted with one or more substituents selected from (1-3C)alkyl,halo, hydroxy, (1-3C)alkoxy, aryl or heteroaryl; L⁴ is absent, CR¹⁴,[BR¹⁵]⁻, (1-3C)alkylene or (2-3C)alkylenylene, said (1-3C)alkylene or(2-3C)alkenylene moieties being optionally substituted with one or moresubstituents selected from (1-3C)alkyl, halo, hydroxy, (1-3C)alkoxy,aryl or heteroaryl; R¹⁴ is absent, hydrogen, (1-6C)alkyl, halo, hydroxy,(1-3C)alkoxy, aryl or heteroaryl; and R¹⁵ is hydrogen or (1-6C)alkyl.18. The compound according to claim 17, wherein Z is a ligand of formula(IIA) or (IIB):

wherein L¹, L² and L³ are a bond, (1-3C)alkylene or (2-3C)alkenylene,said (1-3C)alkylene or (2-3C)alkenylene moieties being optionallysubstituted with one or more substituents selected from (1-3C)alkyl,halo, hydroxy, (1-3C)alkoxy, aryl or heteroaryl; and L⁴ is CR¹⁴,(1-3C)alkylene or (2-3C)alkylenylene, said (1-3C)alkylene or(2-3C)alkenylene moieties being optionally substituted with one or moresubstituents selected from (1-3C)alkyl, halo, hydroxy, (1-3C)alkoxy,aryl or heteroaryl.
 19. The compound according to claim 18, wherein M istitanium.
 20. The compound according to claim 19, wherein X¹ and X² areindependently selected from halo, (1-6C)alkyl and (1-6C)alkoxy.